Data Science Interview Questions with Answers for Freshers

Rupamati Roy — Mon, 06 Apr 2020 08:13:46 +0000

Businesses, governments, and researchers rely on data science to uncover patterns, predict trends, and optimize operations. From personalized recommendations on streaming platforms to medical diagnoses powered by machine learning, data science has become an essential tool in the modern world.

Key Components of Data Science

1. Data Collection The first step in any data science project is gathering data from various sources, such as databases, APIs, sensors, or web scraping. Data can be structured (e.g., spreadsheets) or unstructured (e.g., text, images, videos). Ensuring data quality and relevance is crucial for accurate analysis.

2. Data Cleaning and Preprocessing Raw data is often incomplete, inconsistent, or noisy. Preprocessing includes normalizing data, converting text into numerical representations, and scaling features to ensure compatibility with analytical models.

3. Exploratory Data Analysis (EDA) EDA helps data scientists understand the dataset by visualizing distributions, identifying outliers, and detecting correlations.

4. Feature Engineering This step involves selecting, modifying, or creating new features (variables) to improve model performance. Techniques include dimensionality reduction, one-hot encoding, and polynomial feature creation.

5. Model Building and Machine Learning Data scientists use machine learning algorithms to train models on historical data. Supervised learning (e.g., regression, classification) and unsupervised learning (e.g., clustering, anomaly detection) are common approaches. The choice of algorithm depends on the problem—predicting sales, classifying spam emails, or segmenting customers.

6. Model Evaluation and Optimization Models are assessed using metrics like accuracy, precision, recall, and F1-score. Hyperparameter tuning and cross-validation refine model performance, ensuring generalizability to new data.

Key Techniques in Data Science

Descriptive Analytics Summarizes historical data to identify trends and patterns (e.g., sales reports, customer demographics).

Predictive Analytics Uses statistical models to forecast future outcomes (e.g., stock price predictions, demand forecasting).

Prescriptive Analytics Recommends actions based on data insights (e.g., optimizing supply chains, personalized marketing strategies).

Machine Learning and AI Automates decision-making by training models on large datasets, enabling tasks like image recognition and natural language processing.

Popular Tools and Technologies

– Programming Languages: Python, R, SQL
– Libraries & Frameworks: Pandas, NumPy, Scikit-learn, TensorFlow, PyTorch
– Data Visualization: Matplotlib, Seaborn, Tableau
– Big Data Tools: Hadoop, Spark, Kafka

Applications of Data Science

– Healthcare: Predictive diagnostics, drug discovery
– Finance: Fraud detection, algorithmic trading
– Retail: Recommendation systems, inventory management
– Transportation: Route optimization, autonomous vehicles

Challenges in Data Science

– Data Privacy: Ensuring compliance with regulations like GDPR.
– Bias in Models: Addressing skewed or unrepresentative datasets.
– Scalability: Handling large datasets efficiently.

There are a lot of things that a data scientist should know, I’ll give you a list of data science queries I dealt with in several interviews. If a data scientist can start from here and if it’s a while in this field then it might be a replication, but you’ll find many things from here. I’ll try to start from the basic data science interview questions and cover the first one ahead of time, so let’s get started.

1. What is the difference between supervised and unmanaged machine learning?

Machine Learning – The supervision of a supervised machine requires training in labeling information.

Unsupervised Machine Learning – Studying an unsupervised machine does not require labelled data.

2. Explain how a ROC curve works?

The ROC curve is a graphical representation of the contrast between true positive rates and false-positive rates at various thresholds. It is often used as a proxy for the trade-off between the sensitivity (true positive rate) and false-positive rate.

3. What is selection Bias?

Selection bias occurs when the sample obtained is not representative of the population intended to be analysed.

4. Explain the SVM machine learning algorithm in detail

SVM is a support vector machine, a supervised machine learning algorithm that is used for both regression and classification. If you have n properties in your training data set, SVM will attempt to plot it in the n-dimensional space with the value of each attribute in a specific coordinate. Hyperplanes are used by SVM to separate different classes based on the provided kernel function.

5. What are the support vectors in SVM?

Thin lines represent the distance from the classification to the closest data points called support vectors (dark data points) in a graph. The distance between two thin lines is called the margin.

6. What are the functions of the different kernels in SVM?

There are four types of kernels in SVM.

Linear kernel
The polynomial kernel
Radial Basis Kernel
The sigmoid kernel

7. Explain in detail about the Decision Tree algorithm

A Decision tree is one of the most important supervised machine learning algorithm which is used primarily for regression and classification. The algorithm breaks the data set into smaller subsets, while increasing the associated decision tree. The result is a tree with Decision Nodes and Leaf Nodes. The decision tree can handle partition information and numeric information.

8. What is deep learning?

Deep learning is a subfield of machine learning inspired by the structure and function of the brain called an artificial neural network. We have a lot of numbers of algorithms under machine learning like Linear regression, SVM, Neural network etc and deep learning is just an extension of Neural networks. In neural nets, we consider a small number of hidden layers but when it comes to deep learning algorithms we consider a huge number of hidden layers to better understand the input-output relationship.

9. What is reinforcement learning?

Reinforcement Learning is learning what to do and how to map situations to actions. The end result is to maximise the numerical reward signal. The learner is not told which action to take but instead must discover which action will yield the maximum reward. Reinforcement learning is inspired by the learning of human beings, it is based on the reward/penalty mechanism.

10. What is selection bias?

Selection bias is the bias introduced by the selection of individuals, groups or data for analysis in such a way that proper randomisation is not achieved, thereby ensuring that the sample obtained is not representative of the population intended to be analysed. It is sometimes referred to as the selection effect. The phrase “selection bias” most often refers to the distortion of statistical analysis, resulting from the method of collecting samples. If the selection bias is not taken into account, then some conclusions of the study may not be accurate.

11. Explain what regularisation is and why it is useful

Regularisation is the process of adding a tuning parameter to a model to induce smoothness to prevent overfitting. This is most often done by adding a constant multiple to an existing weight vector. This constant is often the L1(Lasso) or L2(ridge). The model predictions should then minimize the loss function calculated on the regularized training set.

12. What is TF/IDF vectorization?

TF–IDF is short for term frequency-inverse document frequency, is a numerical statistic that is intended to reflect how important a word is to a document in a collection or corpus. It is often used as a weighting factor in information retrieval and text mining. The tf-IDF value increases proportionally to the number of times a word appears in the document but is offset by the frequency of the word in the corpus, which helps to adjust for the fact that some words appear more frequently in general.

13. What are Recommender Systems?

A subclass of information filtering systems that are meant to predict the preferences or ratings that a user would give to a product. Recommender systems are widely used in movies, news, research articles, products, social tags, music, etc.

14. What is the difference between regression and classification of ML methods?

Regression and Classification machine learning methods come under the supervised machine learning algorithms. The major difference is that while in a supervised machine learning algorithm, we need labelled data in order to train our algorithms, moreover, we must provide the correct labels during training, and the algorithm tries to learn the pattern from input to output. If our labels are discrete values then it is a classification problem, e.g. A, B, etc. But if our labels are continuous values then it becomes a regression problem, e.g. 1.23, 1.333 etc.

15. What is ‘Naive’ in a Naive Bayes?

The Naive Bayes Algorithm is based on the Bayes Theorem. Bayes’ theorem describes the probability of an event, based on prior knowledge of conditions that might be related to the event.

What is Naive?

The Algorithm is ‘naive’ because it makes assumptions that may or may not turn out to be correct.

16. Why do we generally use Softmax nonlinearity function as the last operation in-network?

It is because it takes in a vector of real numbers and returns a probability distribution. Its definition is as follows. Let x be a vector of real numbers (positive, negative, whatever, there are no constraints). Then the ith component of Softmax(x) is —
It should be clear that the output is a probability distribution: each element is non-negative and the sum over all components is 1.

17. You are given a data set consisting of variables with more than 30 per cent missing values. How will you deal with them?

The following are ways to handle missing data values:

If the data set is large, we can just simply remove the rows with missing data values. It is the quickest way; we use the rest of the data to predict the values.

For smaller data sets, we can substitute missing values with the mean or average of the rest of the data using a pandas data frame in python. There are different ways to do so, such as df.mean(), df.fillna(mean).

18. For the given points, how will you calculate the Euclidean distance in Python?

plot1 = [1,3]
plot2 = [2,5]

The Euclidean distance can be calculated as follows:

euclidean_distance = sqrt((plot1[0]-plot2[0])**2 + (plot1[1]-plot2[1])**2)

19. What are recommender systems?

A recommender system predicts what a user would rate a specific product based on their preferences. It can be split into two different areas:

Collaborative filtering – As an example, Last.fm recommends tracks that other users with similar interests play often. This is also commonly seen on Amazon after making a purchase; customers may notice the following message accompanied by product recommendations: “Users who bought this also bought…”

Content-based filtering – As an example: Pandora uses the properties of a song to recommend music with similar properties. Here, we look at content, instead of looking at who else is listening to music.

20. How do you find RMSE and MSE in a linear regression model?

RMSE and MSE are two of the most common measures of accuracy for a linear regression model.

RMSE indicates the Root Mean Square Error.

MSE indicates the Mean Square Error.

21. How can you select k fork-means?

We use the elbow method to select k for k-means clustering. The idea of the elbow method is to run k-means clustering on the data set where ‘k’ is the number of clusters.

Within the sum of squares (WSS), it is defined as the sum of the squared distance between each member of the cluster and its centroid.

22. What is the significance of p-value?

p-value typically ≤ 0.05 – This indicates strong evidence against the null hypothesis; so you reject the null hypothesis.
p-value typically > 0.05 – This indicates weak evidence against the null hypothesis, so you accept the null hypothesis.
p-value at cutoff 0.05 – This is considered to be marginal, meaning it could go either way.

23. How can outlier values be treated?

You can drop outliers only if it is a garbage value.

Example: height of an adult = ABC ft. This cannot be true, as the height cannot be a string value. In this case, outliers can be removed.

If the outliers have extreme values, they can be removed. For example, if all the data points are clustered between zero to 10, but one point lies at 100, then we can remove this point.

If you cannot drop outliers, you can try the following:

Try a different model. Data detected as outliers by linear models can be fit by nonlinear models. Therefore, be sure you are choosing the correct model.
Try normalizing the data. This way, the extreme data points are pulled to a similar range.
You can use algorithms that are less affected by outliers; an example would be random forests.

24. How can a time-series data be declared as stationery?

It is stationary when the variance and mean of the series are constant with time.

Here is a visual example:

In the first graph, the variance is constant with time. Here, X is the time factor and Y is the variable. The value of Y goes through the same points all the time; in other words, it is stationary.

In the second graph, the waves get bigger, which means it is non-stationary and the variance is changing with time.

25. How can you calculate accuracy using a confusion matrix?

Consider this confusion matrix:

You can see the values for total data, actual values, and predicted values.

The formula for accuracy is:

Accuracy = (True Positive + True Negative) / Total Observations
= (262 + 347) / 650
= 609 / 650
= 0.93

As a result, we get an accuracy of 93%.

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Basic SEO Interview Questions & Answers for Freshers

Nibedita Panda — Sun, 15 May 2016 17:35:22 +0000

Are you a IT Fresher? Interested to start your Career as a SEO professional. If so let you know SEO is a on-going process. As you know among global Search Engines Google is the King. To serve quality search Google and other search engines updates their algorithm regularly. To achieve success in SEO you required to stay update with latest SEO tricks. Under SEO many thing comes. To be a successful SEO professional is not so easy. I noticed even 10 years experienced SEO professionals having queries related to Search Engine Optimization. So during your interview interviewer can ask any possible questions related to SEO. In this regard here I am sharing basic SEO interview questions and answers.

Difference between Organic & Referral traffics?

Organic traffic refers those visitors who visit your site through Search engines. Compare to referral traffic organic traffic provides better visitors (leads). Let’s take an example, think you have a link related to “Effective home remedies to cure Filaria (Elephantiasis)“. While searching in search engine if a visitor got this link then that traffic is called Organic traffic. In current market the major organic traffic providers are Google and Bing.

Referral traffic is nothing but the traffic comes from link building. As a blog owner you must have Facebook or Twitter accounts. There you have many fans. In this case if you are sharing a link then many one can visit that. These visitor are the best example of referral traffic. Referral traffic generates less sale compare to organic traffic. As a blog owner it’s always wise to consider organic traffic as primary source of business.

Is meta keywords & description matters?

Yes. From my blogging Career I noticed meta keywords are very effective. By including meta keyword in your html page you can get better traffic from Search engines.

Meta description is nothing but those two lines which Google search shows in each search result links. As a best SEO practice always add meta description with your page. While deciding meta description think once the user will view this description in search engines while searching the related keywords.

What is keyword density?

While generating a content the repetition of keywords is called Keyword density. Ranking in Google checks Keyword density. The main ambition behind keyword density is to know the content originality.

Why my blog required a robots.txt file?

Robots.txt is a technique introduced by Google to track which are the pages or folders webmaster want to index or block from the total files of application root folder. For an example in your website you want to block indexing for the “Admin” folder located in root directory. In this case robots.txt helps. Some time during live if you found any page is not compatible to Google webmaster policies you can block this url using robots.txt. Add robots.txt in your application root folder.

What is a Sitemap?

Sitemap is one more way to indicate search engines about your total site structure. I can say this is a page of links. Practice to use both the HTML & XML sitemap. It is healthy practice for on-page SEO.

Do I required both the Sitemap (HTML & XML) in my blog?

Yes. Google or Bing Webmaster tools required a XML based Sitemap. While user required a HTML one. Sitemap guides visitors.

What is the difference between Indexing & Crawling?

Crawling a link in Google is the job of 2 minutes, while indexing takes time. In the early phase many webmasters get confused behind the concept of Crawling and Indexing. After Crawled the link, when it appears in Google Search generally newcomers thought that the link is indexed. But the story is different. Once we Crawled the link it takes minimum 2 to 3 weeks time to indexed in Google. Indexing depends upon link popularity. Depending upon the number of links indexed in Google ROI varies. read more…

How can I know how many pages are indexed in Google or Bing?

To know how many pages are indexed in Google or Bing you required to Search your Domain name. For example “jharaphula.com”. Notice carefully at the top of Search results there is a line like “About 12,700 results (0.68 seconds)”. Here it is saying 12,700 pages are indexed. Similarly to know how much pages Crawled you required to enter the search string with “site:”. For an example “site:jharaphula.com”.

What are Google Webmaster tools?

Without traffic from Google your web is useless. To gain traffic from Google first you need to index your links in Google. That’s why to Google Webmaster Tools. Let’s us discuss in brief what are the features available in Google Webmaster tools & how can you Configure them for your business links Quick Guide to Webmaster Tools.

How to index a link quicker in Google?

Whether Google or Bing you can index your release easily using “Fetch Google” or “Fetch Bingbot” tool from Webmaster tools. In real-time Google do start crawling with in the next 5 minutes after you did fetch google. While Bing takes 24 hours.

Is image optimization effects in SEO?

After Google introduced image search million of visitors are stopped to access other image search sites. Using image there is a chance you can have a visitor. Search engines are unable to read an image. In the cause there are alt & title attributes for image tag. During you integrate an image for your page provide proper keyword related alt & title attributes. This is the only way through which search engines can know about your images. This is the On-page SEO technique of image related sites.

How to Choose a page title?

Keep your web-page title & content heading similar. Prefer to use canonical URLs in place of short URLs. For an example if I want to create a content for “How to teach your Kids?”. It’s more SEO friendly to keep the URL structure like “/how-to-teach-your-kids” in place of “/p=237“. Here I mean to say use a permalink structure in your URL that includes keywords. Search engines will show the URL in their Search results. So, Always prepare URLs user friendly.

How do I test is my pages are Mobile Friendly?

The best tool to test whether your page is Mobile Friendly is https://www.google.com/webmasters/tools/mobile-friendly/. This is owned by Google. Just copy paste the link you want to test for mobile compatibility.

How long it takes to see SEO in results?

All we know SEO is not a Single day job. It required sufficient time & dedication. Minimum 3 months we required to see SEO in results.

How many days Google take to index?

If your site is meeting all Google policies, it may take 30 to 45 days for indexing. Indexing is not a one time job. It runs regularly.

Is manual link building good for indexing?

Leads of Search engine Google or Bing hates manual link building. It’s true during early stage of a blog we required to do manual link building (As we have to Create Social media pages or profile links) for initial publicity. If your blog is Adsense depended then avoid Social sharing or any kind of link building which can affect rank in Google.

What is the benefit of using H1, .. H6 or Bold letters with Content?

This technique is called “Highlight Contents”. Using this technique you can keep a visitor more time on your page. After this while Search engines will index the page they will consider highlighted words as keywords. Highlighting keywords gives better result in Search Engine Optimization.

Do I submit my blog to both the popular Search Engines Google and Bing?

Yes. Bing is the alternative of Google. It’s a Microsoft product. I am not saying Bing will give you more traffic compare to Google but while your link will go parallel in 2 search engines it give competitive results.

How much time Bing takes to Crawl?

After “Fetch Google”, while Google takes 5 minutes to index a link Bing takes 24 hours.

What is the difference between On-page and Off-page SEO?

Which SEO practices we do inside our domain that is called On-page SEO. Link building, Social media marketing, Email marketing or Forum posting comes under Off-page SEO Optimization. Always its wise to do On-page before going for Off-page.

Do I will do link sharing in Social medias?

If you are with AdSense and looking to earn more don’t share links in Social medias. If you are sailing products or with a free site do Social media marketing.

Is Competitor analysis helps in SEO?

Yes. Competitor analysis give correct direction to SEO success.

What is Search Engine submission and how it is useful in SEO?

Globally there are thousand search engines. I know we can get major traffic from Google or Bing but once after a new domain submit your domain to bulk search engines.

Do I will crate a Wikipedia page for my blog?

It’s good to create a wiki page for your blog or web. This gives a permanent backlink with definition to brand name. You must noticed for many keywords Google shows Wikipedia details. So made this with your domain.

Is I required to Track user activities?

Yes. To get success in web you must required to observe your visitors. Visitors analysis gives direction to targeted SEO.

What is Google Analytics?

Google Analytics is a powerful real-time web tracking tool. It’s free to use.

What is a inbound link?

In simple word backlinks are called inbound links. When a user link you link and share in his or her network that is called inbound link. Google loves natural inbound links.

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UI Developer Interview Questions for Experienced Professionals

Nibedita Panda — Sun, 15 May 2016 06:39:06 +0000

I am a UI developer. Having more then 12 years experience with industry. Recently for a better Career growth, I decided to hack a CMM Level 5 company interview. For this reason I did started my preparation and keep attending several technical interviews. My good luck nearly after 45 days I got selected in Infosys. During this period to grab my dream job I applied a trick. From each interview I did collected all UI Developer Interview Questions asked by the interviewer. Slowly I found many questions are common. As you know for UI developer we need to learn HTML, CSS, JAVASCRIPT, JQUERY or ANGULARJS or BootStrap.

If you are having the same profile and going to attained a technical interview in this Saturday or Sunday, prepare the below Questions well. I am sure from this list of UI Developer Interview Questions you will must found above 50% similar questions at your interview.

HTML5 Interview Questions

What are the new elements introduced in HTML5?
Which browsers support HTML 5?
What is datalist in HTML 5?
What are the different advanced form element types in HTML 5?
What is Canvas in HTML5?
What is the use of localStorage in html5?
How to embed a YouTube video using HTML5?
What is the difference between Canvas & SVG?
What’s new HTML5 DocType and Charset?
How can we embed an Audio in HTML5 & what are the audio formats supported by HTML5 Audio Element?
How to embed a Video file in HTML5?
What are the different types of storage in HTML5?
What is Application Cache in HTML5?
Tell me some new markup elements in HTML5.
What does a hgroup tag do?
Which Tags are deprecated in the new version of HTML5?
In HTML5 how to remove local Storage?
What is the difference between cookies & HTML5 Local storage?
How do you make video tag work in Safari version 5?
What is the use of viewport?
How to display repeated data in columns using HTML?

Find the Answers

CSS3 & BootStrap UI Developer Interview Questions

What is CSS?
What are the ways to Apply CSS styles in a HTML documents?
What is the difference between an ID & CLASS selector in CSS3?
Explain me the CSS Box Model.
What is Grouping in CSS3?
What are Child Selectors in CSS?
Give some examples of CSS Pseudo-Class.
What is the use of CSS3 sprites?
Tell me some New features in CSS3.
What is the Syntax of Opacity in CSS3?
What is z-index & How to use it in CSS?
How to set border radius of a div for IE, FF & Chrome using CSS3?
What is clearfix hack in CSS?
What is CSS media queries?
What are the major CSS properties?
What is the difference between Fixed Width Layouts & Liquid Layouts?
What are the difference between Bootstrap 2 & Bootstrap 3?
What are the different classes in Bootstrap 2 & Bootstrap 3?
What are the number of Columns in Bootstrap Grid System?
What are the different Breakpoints in Bootstrap?
What is the difference Container & Container Fluid?
Is it possible to load style sheet dynamically? If yes then how?

Find the Answers

JAVASCRIPT Interview Questions

What are the different data types in JavaScript?
How to Create an Object, Properties & Methods using JavaScript?
What is closures in JavaScript?
Is JavaScript is case sensitive?
What is the difference between “==” & “===” in JavaScript?
How to comment in JavaScript?
How to know Checkbox Status using JavaScript?
How to Create Array using JavaScript?
What isNaN function does in JavaScript?
How to Change Style or Class of an element using JavaScript?
What is Prototypes in JavaScript?
Tell me the difference between Undefined & Null?
Why we use splice() Method in JavaScript?
How to debug JavaScript code?
Which debugger you have used to debug JS code?
What is landscape and portrait? How to set this property?
How will you get device width?
How will you know that web page request is came from small screen device/mobile?

Find the Answers

JQUERY Interview Questions

What is the difference between Jquery & JavaScript?
What you required to Start you first Hello World program using Jquery?
What is document.ready() method in Jquery?
How to select all elements in a page using Jquery?
What are the different type of Selectors available in Jquery?
Explain me the show & hide methods in Jquery?
What are the advantages using Jquery?
What is jQuery noConflict method?
How do you disable or enable a form element using Jquery?
How to Change href attribute of an anchor tag using JQuery?
How to Valid an email using JQuery?
What is JQuery Selector? Explain me with Example.
Explain the animate function in JQuery.
What is jQuery.holdReady() function?
What is JQuery Ajax method?
How animate method works in JQuery?
Can we use two versions of JQuery in the same HTML page?
What is the difference between attr & prop in JQuery?
What is minify version of Jquery?
How to load Jquery from Local if CDN link fails?
What is the use of JQuery $.extend method?
What is JQuery $.map method?
Can I have multiple Jquery document.ready() method in a html page?
What is the difference between document.ready() & body onLoad() method?
How do you control SVG using jquery?
How do you add class using jquery?

Find the Answers

ANGULARJS Interview Questions for UI Developer

What are the key features of AngularJS?
Does Angular use the JQuery library?
How to use ng-repeat in AngularJS?
How to use Filter in AngularJS?
In AngularJS how will you initialize a select box with options on page load?
What are the advantages of using AngularJS?
How to use Controller in AngularJS?
What are the form Validations AngularJS provides?
How to create Custom Directive using AngularJS?
What is 2 way data binding in AngularJS?
What is the CDN link for AngularJS?
How to bind MySQL data to HTML5 using AngularJS?
How to use templateURL in the Directive of AngularJS?
Is AngularJS supports MVVM with MVC?
What is routes in AngularJS?
What is the difference between compile & link functions in AngularJS?
What is difference between Service & Factory?
What is the Syntax for creating Custom Directives in AngularJS?
What is factory? For what purpose it is used?
What is data-binding and how it is achieved in AngularJS?

Find the Answers

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SQL Server Interview Questions for DBA professionals

Nibedita Panda — Tue, 10 May 2016 18:17:10 +0000

SQL Server is a Relational Database Management System designed by Microsoft Corporation. To store data SQL Server is used in many Desktop & Web Applications. If you are a SQL server professional looking to meet Interviewer for better career growth, I can suggest you to go through the below most asked SQL Server Interview Questions.

What is Clustered & Non-Clustered Index in SQL?

Clustered index is a physically rearrangement of data used in your table. It is like the index of a book. One Cluster index is possible for table. Non-Clustered Index are like pointers to the data that is stored in the data page. It is like the reference page of a book.

What is the Difference between Truncate and Delete?

Using SQL Delete we can remove rows from a SQL Table but index is as remain. Truncate delete the rows as well re-index the SQL Table.

What Primary key and Unique key?

Primary key not allows null value. It can be used using foreign key as a referral. Unique key constraints allows nulls value.

How to change Database name in SQL Server?

SQL Server 2005 & for higher versions of SQL Server 2005 we can use Alter database T-SQL statement to rename a database. For lower versions of SQL 2005 we can use exec sp_renamedb stored procedure. Look at the below examples.

SQL Server 2000 & 2005
exec sp_renamedb "TempDatabase", "SampleDatabase"

SQL Server 2005 and later version
ALTER Database "TempDatabase" Modify Name="SampleDatabase"

How to Display current date using SQL Query?

SQL Server has a in-built function called GetDate() which returns current timestamp.

How can we delete duplicate records from a table with no primary key?

It can be done using SET ROWCOUNT command. If you had 2 duplicate rows you can issue SET ROWCOUNT 1, then your DELETE command and finally SET ROWCOUNT 0.

For more Common SQL interview question please refer https://www.deskbright.com/sql/sql-interview-questions/

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Microsoft ASP.NET Interview Questions with Answers

Nibedita Panda — Tue, 10 May 2016 18:15:51 +0000

ASP.NET is a server side technology to create dynamic web applications. It was developed by Microsoft. ASP.NET introduced in January 2002. ASP.NET is a part of MS.NET framework. Are you a MS.NET Professional seeking for a better Job. Prepare the below ASP.NET Interview Questions well before your interview.

What is the difference between Classic ASP & ASP.NET?

Classic ASP is the lower version of ASP.NET. ASP.NET comes with MS.NET Framework. ASP is running under the inetinfo.exe (IIS) when ASP.NET distinct work process using aspnet_wp.exe. It is separate from inetinfo.exe. Classic ASP is not compiled for Apache web server. Using ASP.NET we can execute our app with Apache web server. ASP.NET provides more better performance based application then ASP. The compiling process for ASP & ASP.NET is different. ASP.NET introduced with Common Language Run-time, MSIL, JIT & CLR. The time we are writing code in ASP.NET it get compiled to a byte code format like Java. Due to byte code execution get faster in ASP.NET compare to Classic ASP. ASP.NET introduced code behind concept. Compare to Classic ASP we can write more structured codes in ASP.NET.

What are the different types of validation provided by ASP.NET?

Using validation we protects unnecessary page submissions. Few most common used validations provided by ASP.NET is listed below.

CompareValidator – Compare validation compares values of two input controls.
CustomValidator – Allow programmer to write own validation scripts.
RangeValidator – Checks the user value with in a Specific range.
RegularExpressionValidator – Ensures that the value of an input control matches a specified pattern.
RequiredFieldValidator – Make the control input Mandatory.
ValidationSummary – Displays a report of all validation errors occurred in a Web page.

What are the types of Authentication in ASP.NET?

ASP.NET provides 3 types of Authentications as listed in below.

1. Windows Authentication
2. Form Authentication
3. Passport Authentication

What is view state?

Let assume we have a form with more then ten input controls. I filled out the form and submitted to the server. Assume the form is designed using classic ASP & in between the page submission internet get disconnected. In this situation using back button if I will back to the form then there is no data persist in the input controls. This is a drawback to dynamic web applications. To resolve this view state concept introduced in ASP.NET. View state is responsible to keep state of web controls during page submission. By default view state is enabled in ASP.NET. In back-end view state creates hidden HTML input control to store web control data in encrypted format. With state less HTML view state helps to protect data from Accidental Submission.

What are the state management technique implemented by ASP.NET?

There are 2 types of State management techniques found in ASP.NET. Server Side & Client Side. Server side state management techniques are Session & Application. Client side state management techniques are Hidden Field, View State, Cookie, Control State & Query String.

Explain me the use of Global.asax

Global.asax is a file locating at the root folder of ASP.NET applications. Global.asax provide a way to Application or Module level events in one Central location. Global.asax file derived from HttpApplication class. Default events found in Global.asax are Application_Start, Application_End, Application_Error, Session_Start, Session_End.

What is postback in ASP.NET?

Postback is a technical term to page Submission. Using isPostback event we can check postback happened or not. isPostback returns boolean value.

What are the advantages of code-behind feature?

Code-behind allow programmers to separate business logic & User Interface. Its a new technique introduced by ASP.NET.

What is the difference between user control & custom control?

User Controls can be used for reusable purpose. Custom Control can be used for Global toolbox Control. User control is accessible for current project. When Custom Control can be used Globally. The Extension of user control is .ascx. Extension for Custom Control is .dll. User Control can visible in Solution Explorer when Custom Control is visible in toolbox. Using register tag we can embed an user control but Custom Control used like a normal Control.

What is the use of app_code folder in ASP.NET?

App_Code folder stores Classes, typed data sets etc. If we store any Classes in App_Code it compiles automatically.

What do you mean by multilingual website?

Websites are rotating globally. Let talk about a website jharaphula.com. Here we are getting ten thousand visitors in each day from many angle of world map. When a US customer is watching he/she prefer to look the language English. But the time we have a Customer from France he/she prefer to look in french. Here the concept multilingual comes into. In simple multilingual websites can display the content in various global languages.

How to display all validation errors in one control?

ASP.NET provides five validation controls with ValidationSummary. Using ValidationSummary we can display all validation errors in our ASP.NET page.

What is query string?

Query String is a technique to transfer values from one page to an other web page. Generally query strings are not secured. It will visible at address bar. To write a Query String we can use the following line of code. For more then one query string with the same url we can use &.

https://jharaphula.com?QueryString=test massage&SecondQueryString=sample

How to send email using ASP.NET?

By default ASP.NET provides SMTP mail server. Using few lines of code we can send an email in ASP.NET. Find the script below.

MailMessage mailMessage = new MailMessage();
mailMessage.To.Add("from@email-address.com");
mailMessage.From = new MailAddress("to@email-address.com");
mailMessage.Subject = "test mail";
mailMessage.Body = "Hello world,\n\nThis is a test mail e-mail!";
SmtpClient smtpClient = new SmtpClient("smtp.your-isp.com");
smtpClient.Send(mailMessage);
Response.Write("Mail Sent Successfully.");

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Frequently asked advanced HTML5 interview Questions and Answers

Nibedita Panda — Tue, 10 May 2016 17:40:40 +0000

HTML5 is the 5th revision of basic HTML. HTML5 taking care of user interface during web development. With the advanced features of HTML5 it is getting popular day by day. Leading IT Companies requiting HTML5 developers for their web development farms.

18 frequently asked HTML5 interview Questions

In this session I will let you share the most asked HTML5 interview Questions with answers. If you are looking for a job in HTML5 don’t forget to read the below HTML5 interview questions. I am sure this will help you to win a better Career.

1. What are the new elements introduced in HTML5?

In HTML5 for better graphics Canvas is newly introduced. Canvas is the area in a HTML5 document where we can draw graphics using any client scripts.

HTML5 introduced 5 new media elements. These elements are Audio, Embed, Source, Track & Video. Using Audio & Video tag we can easily embed audio or video files to our HTML5 web pages. Embed tag act like an object for external sources. Source tag defines the audio or video file path. Track defines the layer of audio or video file. Compare to other techniques we followed to integrate audio or video in the lower versions of HTML5 these new media elements are more powerful & effective.

3 new form elements added in HTML5 compare to HTML4. These form elements are datalist, keygen & output. Using datalist we can pre-defiend options in input controls of HTML5. Keygen help in security. It generates unique encrypted key for forms. Output defines the result of a Calculation dynamically.

Other structural elements added in HTML5 are like article, aside, dialog, header, footer, main, mark, nav, progress, section, time & summary.

2. Which browsers support HTML 5?

HTML5 is an advanced markup language. It supports all the latest browsers. Internet Explore, Mozilla Firefox, Google Chrome, Safari & Opera like all common used browsers provides compatibility for HTML5 & all its advanced features.

3. What is datalist in HTML 5?

Like the select option in HTML5 datalist is one more additional feature. It used for input fields to provide auto-complete feature. Look at the below image you can understood well.

Example

4. What are the different advanced form element types in HTML 5?

In HTML5 the following element types are available.

Date Url Datetime-local Time Range Email Telephone Color Search Number

Example

5. What is Canvas in HTML5?

Canvas is a new element introduced in HTML5. Canvas used to draw graphics in HTML5. To draw using Canvas we can use Client Script like JavaScript or Jquery. In the following example I am showing how to declare a Canvas and how to draw in a Canvas.

6. What is the use of localStorage in html5?

In HTML5 localStorage is an Object to store data in Client Computer. This data has no expiry it can be for next day, a week, a month or even more then a year. LocalStorage can created using name & value pair. See the below example.

//To Store using LocalStorage
localStorage.setItem("name", "John Smith");
//To Retrieve from LocalStorage
document.getElementById("lblname").innerHTML = localStorage.getItem("name");

7. How to embed a YouTube video using HTML5?

From the list of HTML5 Media Elements we can use embed tag to show YouTube video in a HTML5 web pages. Look at the example below.

8. What is the difference between Canvas & SVG?

Canvas is a advanced element in HTML5, 2d graphics we can draw on a Canvas using JavaScript. SVG is a language to describe 2d graphics in xml. HTML5 Canvas doesn’t support event handlers. SVG supports event handler. SVG can do better text rendering then Canvas. Canvas is suitable to use in game applications but using SVG its not better to develop game applications.

9. What’s new HTML5 DocType and Charset?

HTML5 is now not a subset of SGML. DocType is relaced the SGML. Example shown below.

About Charset in HTML5 it uses UTF-8 encoding. Example Shown below.

10. How can we embed an Audio in HTML5 & what are the audio formats supported by HTML5 Audio Element?

The newly introduced media elements Audio & Source help us to embed Audio file in HTML5 document. Audio tag supports 3 basic audio formats. Ogg, mp3 & Wav. Look at the example below.


Your browser doesn't support audio tag.

11. How to embed a Video file in HTML5?

The newly introduced media elements Video & Source help us to embed Video file in HTML5. Video element in HTML5 supports ogg, webm & mpeg4 video formats. Look at the below example how to embed video in HTML5.


Your browser does'nt support video tag.

12. What are the different types of storage in HTML5?

In HTML5 two type of storage introduced. These are SessionStorage & LocalStorage.

Session Storage – SessionStorage stores the data for a specific Session.
Local Storage – LocalStorage stores the data for long duration even after the browser closed.

13. What is Application Cache in HTML5?

Among many key features in HTML5 “Application Cache” enables to store all the browsed websites locally as its off-line version. In the consecutive call to same website Application Cache helps to fetch few contents only from the server. It uses the local copy & help to reduce HTTP requests. This technique in HTML5 helps for a better performance. Application Cache can achieved using manifest with HTML tag.

Manifest file comes with three sections. CACHE MANIFEST, NETWORK & FALLBACK. Cache manifest is the section where which files we will declare those files will store after they are downloaded for first time. Logo, js files are image files are basically we declare in Cache manifest. Network section is for those files require a connection to the server. Files declared under Network section never cached. File listed under Fallback fallback pages if a page is inaccessible.

Example of Application Cache manifest File

CACHE MANIFEST /app-theme.css /company-logo.gif /main.js

NETWORK: login.php

FALLBACK: /html/ /offline.html

14. Tell me some new markup elements in HTML5.

header – The top most part of a html document. It can include navigation.
footer – The most below part of a html document. It can hold Copyrights information.
section – Section can be the header, footer or it can be content paragraphs.
nav – To create easy Navigation.
time – Defining the time or date.
progress – An indicator to work durations.
article – specify independent, self-contained contents.

15. What does a hgroup tag do?

The hgroup tag in HTML5 is used to group a set of h1 to h6 elements. Find an Example below.


What is your Age?
Your Name Please?

16. Which Tags are deprecated in the new version of HTML5?

Acronym, applet, basefont, big, center, dir, font, frame, frameset, noframes, strike & tt are the deprecated HTML5 elements compare to the lower version HTML4.

17. In HTML5 how to remove local Storage?

Local Storage data can be removed using 2 methods in HTML5. One is removeItem() & other one is clear(). Using removeItem method we can delete specific key value pair from local Storage. Using clear method it clears all the data stored in local Storage.

18. What is the difference between cookies & HTML5 Local storage?

Local storage is only accessible at client end. To access local storage in server end we need to use Post() or Get() method. Cookies can accessible at Client & Server end. Local storage stores 5 mb per domain. Cookies can store 4096 bytes per cookies. There is no expiry date for local storage to delete local storage variable we need to do delete programmatically. While creating a cookie we can set expiry date for the cookies. Cookies are less secure then HTML5 Local storage. Local storage is an advanced concept to HTML5. Cookies is an older technology.

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25 Jquery Interview Questions and Answers for Experienced or Freshers

Nibedita Panda — Tue, 10 May 2016 17:18:25 +0000

Jquery is an optimized lightweight JavaScript Library. It helps to develop more functional applications using less line of codes. You can say Jquery is the enhanced version of JavaScript. It contains many in-built functions to interact with HTML & JavaScript. You can download Jquery from jquery.com. Jquery is popular due to its reuse-ability. Jquery saves programmer time. For your successful interview read our Jquery Interview Questions and Answers. These Jquery interview questions are useful for both Experienced & Freshers professionals.

Why use JQuery over plain JavaScript?

Cross-Browser Compatibility: jQuery handles browser inconsistencies, ensuring code works uniformly across different browsers.

Simplified Syntax: jQuery reduces verbose JavaScript code with shorter, more readable methods.

DOM Manipulation: Selecting and modifying DOM elements is easier with jQuery’s selector engine.

AJAX: jQuery simplifies asynchronous HTTP requests with methods like `$.ajax()`.

Extensibility: Plugins and custom functions can be easily integrated.

25 Selective, Frequently asked Jquery Interview Questions and Answers

A compilation of interview questions related to jQuery is available for those preparing for technical assessments. It is essential to focus on the specific language required for responses and adhere to any relevant guidelines during the interview process. This resource aims to assist candidates in understanding key concepts and functionalities of jQuery, ensuring they are well-prepared to demonstrate their knowledge effectively.

1. What is the difference between Jquery & JavaScript?

JavaScript is a programming language formalized in the ECMAScript standard. When Jquery is a library developed using JavaScript. Jquery contain many common used JavaScript functions. Using Jquery we can prepare cross-browser compatible applications with less line of codes. Compare to JavaScript Jquery save time of a programmer & Applications developed using Jquery is easy to debug.

2. What you required to Start you first Hello World program using Jquery?

To start with Jquery “Hello World” program you need a text editor and the downloaded version of Jquery file. You can download Jquery file from jquery.com. To integrate this on your page you can refer the line below.

After integrated Jquery file in your HTML page. Write the following lines of code.

$document.ready(function() {
alert('Hello World!');
});

3. What is document.ready() method in Jquery?

Document.ready() method is used to execute Jquery after the HTML Document loaded to the Client Browser. In below I am sharing my first Jquery program to show you an example of document.ready() method.








My First Jquery Program.

4. How to select all elements in a page using Jquery?

Using all selector in Jquery we can select all elements in a HTML page. Syntax used to select all elements is *. Look at the example below. In document.ready method here I am applying font style to all elements in a HTML page.

$("*").css("font-size", "14px");

5. What are the different type of Selectors available in Jquery?

jQuery selectors are used to find and select HTML elements based on their name, ID, classes, types, attributes, values, and more. Once selected, these elements can be manipulated using jQuery methods. In Jquery we have 3 types of Selectors. These are CSS selector, Xpath selector & Custom selector.

6. Explain me the show & hide methods in Jquery?

Show & hide are the ready-made methods of Jquery to Show or Hide any HTML element. Using show or hide methods in Jquery we can also add duration for showing or hiding an element. Show and Hide methods in Jquery accepts 2 parameters speed & callback. Look at the example below using Jquery Show & Hide methods.








This is a sample text.

7. What are the advantages using Jquery?

Jquery is a JavaScript Library which gives ability to develop high performance web applications using less line of Codes. There are many advantages using Jquery.

A. Jquery is Cross-browser Compatible. With Jquery stuffs we don’t need to worry about Browser Compatibility.

B. Jquery is easy to learn & implement. To do a small animation in client-side we must need to write 10 to 15 lines of JavaScript codes. Using Jquery this can be done using one function. Jquery comes with many in-built functions. Jquery improves programers time by delivering quality outputs.

C. Jquery helps to improve the performance of a web-application.

D. In a HTML Document Jquery is easy to use for DOM manipulation & traversal.

E. Jquery Supports Event detection and handling.

F. Jquery is rich with AJAX Capability. Thousand of free plugins are available for Jquery.

8. What is jQuery noConflict method?

JQuery uses $ sign as the alias. There are many other JavaScript libraries those uses $ sign. To prevent conflict with other libraries methods or different versions of JQuery, JQuery introduced noConflict method. You can use noConflict using the following Syntax.

$.noConflict();

Let’s assume in your application you want to use two versions of JQuery. Version 1.1.2 & Version 1.1.3. In this case to prevent conflict among the different versions you can do the following.

9. How do you disable or enable a form element using Jquery?

Let we have an input box with id txtName. Two more buttons are there btnEnable & btnDisable. On click of enable button I want to enable the input box & on click of disable button I want to disable the input control. Look at the example below.

$('#btnEnable').click(function() {
$('#txtName').attr('disabled', false);
});

$('#btnDisable').click(function() {
$('#txtName').attr('disabled', true);
});

10. How to Change href attribute of an anchor tag using JQuery?

JQuery provides attr() method to change control attributes. Let us assume we have a button control with id “btn1”. On this button click we want to assign link to a anchor tag named “link1”.

$('#btn1').click(function() {
$('#link1').attr('href','http://google.com');
});

11. How to Valid an email using JQuery?

To valid email id using JQuery create a separate function ValidEmail(). Pass the email id as a parameter. Using Regex we can valid the email id. Example shown below.

function ValidEmail(EmailID) {
var filter = /^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;
if (filter.test(EmailID)) {
return true;
}
else {
return false;
}
}

12. What is JQuery Selector? Explain me with Example.

JQuery selectors used to select group of HTML elements. Additionally JQuery supports CSS & ID Selector. JQuery Selector always starts with a dollar sign & parentheses. In case of we want to select all the div’s using Jquery Selector. The Syntax is as follows.

$(div)

Using CSS selector in JQuery we can select a control from its CSS class name. Let us we have a div with class “StyleDiv”. CSS Selector in JQuery uses dot with the class name to select the element. It can be selected using the following CSS selector.

$('.StyleDiv')

About ID Selector in JQuery we can select a control which have an ID. Let us we have a div with ID “MasterDiv”. ID selector is the most fastest JQuery selector compare to other selectors. It can be used using the following Syntax. # is the key to select a control using ID.

$('#MasterDiv')

13. Explain the animate function in JQuery.

The animate() function in jQuery is a robust tool for creating dynamic, engaging web animations with minimal effort. By understanding its parameters, leveraging callbacks, and following best practices, developers can enhance user experience while maintaining clean, efficient code. Whether animating simple movements or complex sequences, jQuery’s `animate()` function remains an indispensable asset in modern web development. In a HTML page for Client side animations JQuery provides animate function. Animate function accepts 4 parameters. Syntax of Animate function is as below.

$(selector).animate({params}, [duration], [easing], [callback])

Param defines CSS property on which we want animation. Using Duration we can set how long our animation will run. Easing is the controller to transition. Callback is the function which you can run just after the animation completed.

14. What is jQuery.holdReady() function?

Using jQuery.holdReady() function we can hold or release the execution of jQuery ready event in a HTML page. Jquery holdReady function accepts boolean parameters. To hold the execution we can write the following syntax.

When we want to release the ready event we need to set holdReady to false as shown below.

[code lang="jjQuery.holdReady(false);

15. What is JQuery Ajax method?

JQuery Ajax method perform an asynchronous HTTP request. It accepts 2 parameters. URL & the settings as shown as below.

Using JQuery Ajax method we can retrieve the DOM object value. Let us have a page demo.html. What we want is to extract the DOM object body contexts. After retrieve contexts we want to disable to the button control. Look at the example shown below.

$.ajax({
url: "demo.html",
context: document.body
}).done(function() {
$( this ).addClass( "class-disable" );
});

16. How animate method works in JQuery?

To made 2D animations easy, JQuery introduced animate method. It accepts 3 parameters. First one is the params. Using params we provides CSS to the future animation. Speed is the second parameter, which decides the speed of animation frames duration. Last parameter is Callback. It is a function which executes just after the animation completed. Let you see an example below.

$("btnAni").click(function(){
$("div").animate({
left:'350px',
opacity:'0.6',
height:'250px',
width:'180px'
});
});

17. Can we use two versions of JQuery in the same HTML page?

Yes. We can use multiple versions of JQuery in a same HTML page. To do so JQuery provides noConflict method. Lets take an example. In below code I have 2 versions of JQuery. JQuery-1.1.2 & JQuery-1.2.3.

To use JQuery 1.2.3 we can call JQuery_3 in place of $ sign. For JQuery 1.1.2 we can replace $ sign with JQuery_2.

18. What is the difference between attr & prop in JQuery?

In case we are changing the attribute of a control using jquery we use attr. For an example on a button click I want to update an anchor tag hyperlink. Look at the code below.

$('#btnclick').click(function() {
$('#myanch').attr('href','http://google.com');
});

To get the value & property we use prop method in jquery. Let you have a checkbox & you want to know its state. Checked or un-checked. In this case we use prop. Look at the code below.

$('#btnclick').click(function() {
$('#mycheckbox').prop('checked');
});

To remove property we use removeProp in JQuery.

19. What is minify version of Jquery?

Minified version of JQuery is nothing but the same copy of Jquery library file but it is in compressed form. The extension of minify version is comes with .min.js. Minified version provides more performance then the normal one. In the cause many web development farms prefer to use minify version in there production server. To convert your JavaScript file for minify version there are many online providers. You can find then using Google search.

20. How to load Jquery from Local if CDN link fails?

In a web application to refer Jquery library many of us follow CDN link pattern. But for more safty approach it is better to provide both the options to access library file. In the below script I refered Jquery-1.10.2.js using CDN link as well I am checking if this fails then I am fetching the same library file from my server scripts folder.

21. What is the use of JQuery $.extend method?

Using JQuery $.extend method we can merge the contents of two or more objects into the first object. The syntax is as follow.

var obj-0 = $.extend({}, obj-1, obj-2);

Let’s we have two array’s arr-i & arr-j. During development what I need is I want to merge arr-j values to arr-i. In this case jquery extend method helps.

$.extend( arr-i, arr-j );

But this is not recursive. To merge two objects recursively we need to pass the first parameter value true to extend method. As shown in below.

$.extend( true, arr-i, arr-j );

22. What is JQuery $.map method?

The jQuery `$.map()` method is a powerful utility function designed to transform arrays or array-like objects by applying a callback function to each element. It simplifies data manipulation tasks, allowing developers to process collections efficiently without writing extensive loops. This method is particularly useful when working with dynamic data, such as API responses or DOM elements, where transformations are frequently required.

How $.map() Works

The `$.map()` method accepts two primary arguments:

1. The input array or object – This can be a standard JavaScript array, a jQuery object, or any array-like structure.
2. A callback function – This function processes each element and returns a modified value.

The syntax is as follows:

javascript $.map(array, callback(element, index))

The callback function receives two parameters: – `element` – The current item being processed. – `index` (optional) – The index of the current element.

The method returns a new array containing the transformed values, leaving the original array unchanged.

Jquery map method is used to translate items of an Array or object to new array of items. Let’s take an example.

var tempArray = { "name":"biswabhusan", "age":32, "designation":"UI lead" };
var realArray = $.makeArray( tempArray )
$.map( realArray, function( val, i ) {
// Do something
});

23. Can I have multiple Jquery document.ready() method in a html page?

Yes. We can declare any number of document.ready() method in a same HTML page.

24. What is the difference between document.ready() & body onLoad() method?

Document.ready() is a Jquery method. During page loading it executes just after DOM (Document Object Model) elements are loaded. Where HTML body onLoad() method loads after everything get loaded from a HTML document body. It includes DOM, images & related resources.

In a HTML document we can have one & only one body onLoad() method. While we can use multiple document.ready() methods as required.

25. What is the key differences between $.map() and JavaScript’s Array.map()?

While both `$.map()` and JavaScript’s native `Array.map()` perform similar operations, there are notable differences:

Handling Non-Array Objects – `$.map()` can process array-like objects (such as jQuery collections), whereas `Array.map()` strictly requires an array.

Null and Undefined Values – `$.map()` automatically excludes `null` or `undefined` values from the result unless explicitly returned.

Return Behavior – If the callback returns an array, `$.map()` flattens it into the resulting array, whereas `Array.map()` preserves nested arrays.

Conclusion

jQuery remains a powerful tool for web development, especially for DOM manipulation and AJAX operations. Mastering these interview questions will help you demonstrate proficiency in jQuery and enhance your chances of landing a job. Whether you’re a beginner or an experienced developer, understanding these concepts ensures you can efficiently work with jQuery in real-world applications.

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Advanced JavaScript Interview Questions and Answers

Nibedita Panda — Tue, 10 May 2016 17:16:12 +0000

Today there are plenty of vacancies for JavaScript developers. If you are one among them who is searching a job for JavaScript, I can suggest you to take a look at the below JavaScript interview Questions and Answers. Hope this will help you in your Interview.

Years back JavaScript is one of the famous client-side Scripting language. In web development JavaScript helps to reduce load on server by doing minimal jobs at client end. Lets take an example where and how JavaScript works.

Assume in a web page we have an input field where user need to provide his/her email id for subscription. Before take the user email id into our customers database we need to verify was the user provided a valid email id. Else it is a fake record to our storage. To do this we have many methods in server-side scripting but by checking a valid email id in server it uses server resource as well it increases the load time. Even in real-time a busy user need to wait for server response to verify email validation. Here client-side script takes role. JavaScript compiler resides in Client browser and it can check any email validation with out using server-side scripting. This helps to develop more better performance based web applications.

1. What are the different data types in JavaScript?

JavaScript has Dynamic Data types. The different types of Data types JavaScript supports are String, Number, Array, Object, Boolean and Undefined. JavaScript is so smart. Using var only we can create any kind of Data types. Look at the example below.

//String Datatype
var str = “this is a string datatype”;
//Number Datatype
var num = 34;
//Boolean Datatype
var bool = true;
//Array Datatype
var arr = [“rosa”, “rupak”, “rohini”];
//Object Datatype
var obj = { name: “biswabhusan”, age: 33, designation: “Team Leader”};
//Undefiend Datatype
var und;
//Null Datatype
var noval = null;

2. How to Create an Object, Properties & Methods using JavaScript?

JavaScript is a client-side technology. It supports Object Oriented Programming feature. In JavaScript almost everything is an Object. String, Dates, Functions & Array are the example of JavaScript objects. You can create your own object in JavaScript. There are several ways to do this.

In this block I am presenting 2 ways to create object in JavaScript. Let us talk about an employee object. For the below employee object we have the properties like first name, last name, age & designation.

var employee = {
firstName:"John",
lastName:"Smith",
age:40,
designation:"Team Lead"
};

employee = new Object()
employee.firstName = "John"
employee.lastName = "Smith"
employee.age = 50
employee.designation = "Team Lead"

Now in the above employee object I need to implement a method which will return full name of the employee. Look at the below example.

var employee = {
firstName:"John",
lastName:"Smith",
age:40,
designation:"Team Lead",

getFullName : function() {
alert(employee.firstName + " " + employee.lastName);
}
};

Here getFullName is the method using which I am extracting full name of an employee. Like the above examples you can create Object, Properties & Methods in JavaScript.

3. What is closures in JavaScript?

Before make you clear about closures in JavaScript. Let us discuss the variable scope in JavaScript. Using JavaScript we can declare a variable either local or in global Scope. Variables in local Scope mean we can use this variable inside that function only, where it is declared. In-case of global variables we can use it in any functions. Lets take an example.

Example of Local Scope Variable

function demoFunc() {
//Local variable b
var b = 5;
return b * b;
}

Example of Global Scope Variable

//Global variable b
var b = 5;
function demoFunc() {
return b * b;
}

Now to make you understood closures in JavaScript let us discuss one practical programming problem. Suppose you want a use a function increaseCounter() to increase 1 by 1 in each call. In this function what we are doing, we are increasing a global variable by 1 in each of this function call.

var counter = 0;

function increaseCounter() {
counter += 1;
}

increaseCounter();
increaseCounter();

In this case without the function call also we can update the counter variable as its in Global Scope. If I am making the counter variable to local scope this function will reset the counter in each call. Here JavaScript closures works. See the example below.

Example of using JavaScript closures

var increaseCounter = (function () {
var counter = 0;
return function () {return counter += 1}
})()

increaseCounter();
increaseCounter();

4. Is JavaScript is case sensitive?

Yes, JavaScript is case sensitive. Lets talk about a DOM object getElementById is not same as getelementbyid.

5. What is the difference between “==” & “===” in JavaScript?

== & === both are used to Compare equality. Triple equal doing additional checking for variable types. Look at the example below.

var a = 0;
var b = "0";

if (a==b){
alert('The value of a & b are same.');
}

if (a===b){ } else {
alert('Data type mismatch for a & b.');
}

6. How to comment in JavaScript?

In JavaScript comments can be added using 2 ways. One is Line Comment. This can be done using 2 forward slashes (//). For block commenting use /*………………..*/.

Example of JavaScript Commenting

// This is a Line Comment in JavaScript
var a = 0;
var b = "0";

/* This is block Comment in JavaScript
if (a==b){
alert('The value of a & b are same.');
}

if (a===b){ } else {
alert('Data type mismatch for a & b.');
}*/

7. How to know Checkbox Status using JavaScript?

Let we have a HTML Checkbox Control in our page with the id “chkTemp”. To check the Status of this check box we can write the following JavaScript.

var ChkStatus = document.getElementById('chkTemp').checked;
document.write(ChkStatus);

8. How to Create Array using JavaScript?

With JavaScript Syntax there are 2 ways to declare an Array. Look at the examples below.

// First way to Declare JavaScript Array
var empName = new Array();
empName[0] = "Rajesh Sukla";
empName[1] = "Rakesh Srivastab";
empName[2] = "Ritesh Deshmukh";

// Second way to Declare JavaScript Array
var empName = new Array("Rajesh Sukla", "Rakesh Srivastab", "Ritesh Deshmukh");

9. What isNaN function does in JavaScript?

isNaN function does number checking in JavaScript. It returns true if the argument doesn’t seems to be a Number.

10. How to Change Style or Class of an element using JavaScript?

Look at the example below here I declared a div with id txtSample. Using Document Object Model here I am extracting the div control by its id. Applying style font-size 20px on div. In the next line of code I am assigning a css class to my div with the name anyclass.

document.getElementById("txtSample").style.fontSize = "20px";
document.getElementById("txtSample").className = "anyclass";

11. What is Prototypes in JavaScript?

Using Prototypes in JavaScript we can define methods to all instance of an object. The method applied to prototypes stored in memory. With each instance of the object we can access it. Lets watch the following example.

function Emp(name, designation){
    this.name = name;
    this.designation = designation;
}
function view(){
    return this.name + " is a " + this.designation + "!";
}
Emp.prototype.view = view;
var emp1 = new Emp('Biswabhusan', 'Module Lead');
alert(emp1.view());

//Outputs "Biswabhusan is a Module Lead!"

12. Tell me the difference between Undefined & Null?

When Null returns an object Undefined returns nothing or Undefined. Undefined means that the variable has not been declared or initialized. By declaring null to a variable it contains empty value but it is initialized. Let’s take an example. In my app I referred the CDN link of Jquery library. If using typeOf I am getting typeOf(jquery) undefined it means CDN link of jquery fails to load. While declaring a variable it’s wise to initialize the variable with Null value.

13. Why we use splice() Method in JavaScript?

Splice() Method is used to manipulate JavaScript array. The syntax is Array.splice(index, how many, item 1,…..,item N). Here index & how many is required parameters. Where items are optional. Index accepts numbers from which position we want to add or remove array elements. How many says how many number of elements we want remove from the supplied index value. Item 1 to N adds this values after the index position.

To make your understanding clear please find the below example.

/* Inserting one element to the existing array using Splice method */
var fruits = ["A", "B", "C", "D"];
fruits.splice(2, 1, "E", "F");

Output after splice - A, B, E, C, D

/* Applying only splice method not inserting any elements */
var fruits = ["A", "B", "C", "D"];
fruits.splice(2, 2);

Output after splice - A, B

The post Advanced JavaScript Interview Questions and Answers appeared first on OneStop Shop.

Frequently asked advanced CSS3 Interview Questions and Answers

Nibedita Panda — Tue, 10 May 2016 17:14:09 +0000

In Web Development CSS plays a great role to apply Styles. Using CSS we can Centralize Styles for a Web app. For an example if in a html page you have 10 paragraphs, using CSS3 class we can change all the paragraph style by updating color code in one CSS class. Today there are plenty of vacancies available for UI developers.

16 Frequently asked CSS3 Interview Questions

Among the skill sets of a UI professional, CSS3 is one of the major Skill. In this week-end are you planning to attained an interview for UI developer? If so look at our advanced CSS3 interview questions in below. I am sure these questions and answers will help you to hack the interviewer.

1. What is CSS?

The full name of CSS is Cascading Style Sheet (CSS). It used to apply Styles in HTML documents. CSS centrally stores the style. It’s better to keep a CSS file rather then writing CSS classes in the html head with Style tag. In professional web development practice to avoid in-line CSS. The extension of CSS3 file is .css.

CSS is an indispensable tool in web development that empowers developers to create visually appealing, structurally sound, and efficient websites. By following best practices and leveraging the full potential of CSS, one can elevate their web projects to new heights. Whether you’re a seasoned developer or just starting, mastering CSS is crucial for anyone looking to thrive in the realm of web design.

2. What are the ways to Apply CSS styles in a HTML documents?

There are 4 different ways to Apply CSS3 in a HTML document. These are In-line CSS, Embedded CSS, Linked CSS & Imported CSS.

Example

In-line CSS –

This is in Red Color

Embedded CSS –

Linked CSS –

Imported CSS – @import url(‘/css/color.css’);

3. What is the difference between an ID & CLASS selector in CSS3?

Using ID selector we can apply style to a specific element while using class we can apply the same style to many.

The ID selector is used to style a single HTML element by its unique identifier. In the markup, this identifier is assigned using the `id` attribute. IDs must be unique within a webpage; therefore, only one element can possess a specific ID at any given time. This uniqueness makes the ID selector particularly useful when you want to apply a specific style to a single component.

On the other hand, the CLASS selector is more flexible and can be used to style multiple elements simultaneously. The class can be applied to any number of HTML elements, and it allows for a shared style across these elements. To define a class, you simply use the `class` attribute in your HTML elements.

4. What is Grouping in CSS3?

About CSS3 Grouping let us discuss an example to make you more clear on this. Some time in our page we have h1, h2, h3 .. h5, h6 tags. If I want to apply font color red to all this tags. Here grouping comes. Grouping selectors in CSS3 enables designers to write cleaner code by combining multiple selectors that share the same styles. Instead of writing repetitive rules for each selector, grouping allows us to consolidate these rules into a single declaration. This method not only improves readability but also enhances maintainability, which is crucial as applications grow more complex.

Grouping is particularly beneficial in cases where multiple tags share similar styling. Imagine if you later decide to change the color of all headings from red to blue. With the grouped selector approach, you only have to change one rule, as opposed to updating each individual selector, which drastically reduces the risk of errors.

Let you watch the below example. It will clear your understanding.

h1, h2, h3 {color: red;}

5. What are Child Selectors in CSS?

In CSS3 Child Selector used to to apply styles upon the child elements of a parent elements. Using child selectors can help maintain the integrity of your styles. By applying styles specifically to child elements, you avoid unintended consequences on other elements that may have similar classes or tags but are not direct children. This selective styling makes your CSS more efficient and prevents style conflicts, especially in complex layouts.

Additionally, child selectors enhance performance as the browser has to do less work in matching elements. This can be particularly important on pages with a large DOM.

Lets for an example I have a ul tag inside a paragraph. Here ul is the child element of paragraph. To apply CSS styles we can use the following CSS3 syntax.

p > ul { font-size:20px; }

6. Give some examples of CSS Pseudo-Class.

Using CSS pseudo Class we can add special effects to some Selectors.

Example of Anchor Pseudo Class

/* style for unvisited link */
a:link { color: #FF0000; font-size:12px; }

/* style for visited link */
a:visited { color: #00FF00; font-size:14px; }

/* on mouse over link */
a:hover { color: #FF00FF; font-size:16px; }

/* selected link */
a:active { color: #0000FF; font-size:12px; }

Example of First Child Pseudo Class

p:first-child { color: #0000FF; }

7. What is the use of CSS3 sprites?

In a web page we are using many images to decorate. All these image takes time to load individually. This old fashion of image loading increases http request to server. It hampers the performance of web page. To resolve this CSS3 comes with sprites. It helps to keep many images in a single file. Due this it decreases the http request to the server. Gives better performance and taking less server time.

Not only does using CSS3 sprites cut down on load times, but it can also lead to better performance on mobile devices and slower networks. As mobile internet speeds vary considerably, optimizing web assets can make a crucial difference in accessibility.

Although managing sprites can initially seem daunting, it simplifies asset management over time. Instead of tracking multiple images, developers can work with just one file. When an update is needed, such as changing an icon or image, developers can modify the sprite and then update the CSS to point to the new positions of the images.

8. Tell me some New features in CSS3.

CSS3 is the 3rd revision of CSS. Compare to CSS2 CSS3 introduced the following new features.

Calculating value with calc()

In CSS2 to set dynamic width we use JavaScript or Jquery. This problem is resolved in CSS3. CSS3 introduced calc() function. For an example if you want to set a div (#container) with 100px less then the 100% width then you can do the following using CSS3 calc method.

#container {
/* Calculate the width Dynamically */
width: calc(100% - 100px);
margin: 0 auto;
}

Web-fonts

In the early age of programming we have some limited fonts. To add a new font we need to download the respective font file (*.ttf) & need to copy that file into fonts directory. CSS3 web-fonts with Google fonts resolve this problem in the way of web development. Today fonts are not only displaying Alphabets or Numbers it is also taking care of icons. Let’s talk about the popular web-font “Font-Awesome”. It comes with scalar vector icons.

CSS3 by implementing @font-face make font integration much more easier then the classical web designing. After applying @font-face we can use font or font-family to integrate the web-fonts in our application. Look at the example below.

@font-face {
font-family: 'demo-web-fonts';
src: url('https://www.example.com/fonts/demofont.woff') format('woff'), 
/* Compatible for Chrome 6+, Firefox 3.6+, IE 9+, Safari 5.1+ */
url('https://www.example.com/fonts/demofont.ttf') format('truetype');
/* Compatible for Chrome 4+, Firefox 3.5, Opera 10+, Safari 3—5 */
}

then we can refer this web-fonts using the following syntax.

body {
font-family: 'demo-web-fonts', Fallback, sans-serif;
}

CSS3 Animation

CSS3 Selectors

In addition to CSS2, CSS3 introduced some new Selectors. Using these selectors you can choose DOM elements based on their attributes. So you don’t need to specify classes & id for each elements.

CSS3 Rounded Corner

In the old age its difficult to round the corner of a div or paragraph. This problem is addressed by CSS3. Using border-radius property we can easily round the corner of HTML elements.

Border Image

Using border-image feature in CSS3 you can display custom image to border. To show you an example in below I applied border-image to a paragraph element. This paragraph is width of 300px. Text added in paragraph is center aligned. To apply border-image first I applied border with 20px height & background transparent. In border image I referred an demo image.

p {
text-align: center;
padding: 15px;
width: 300px;
margin: 0 auto;
border: 20px solid transparent;
border-image: url(https://example.com/img/border-image.png) 20 20 round;
}

CSS3 Box Shadow

Using box shadow you can create a drop shadow for a HTML elements. In CSS3 using the property box-shadow this can be achieved by writing a single line of CSS code.

CSS3 Text Shadow

In the old age of web its quite difficult to add Text Shadow over a web page text. In CSS3 it is done using text-shadow property. Using a single line of code we can achieve with a text label.

9. What is the Syntax of Opacity in CSS3?

style="opacity:0.4; filter:alpha(opacity=40)"

Firefox uses the property opacity:x for transparency, while IE uses filter:alpha(opacity=x).

10. What is z-index & How to use it in Advanced CSS3?

The z-index property specifies the stack order of an element. Using z-index we can bring an element with greater stack order is always in front of an element with a lower stack order.

In complex layouts with multiple overlapping elements, it’s crucial to create a clear hierarchy of `z-index` values. By strategically assigning values, you can manage which elements appear in front without confusion. For example, a modal dialog box should have a higher `z-index` than the page content to ensure it stands out. When using CSS animations, pay attention to `z-index` transitions. Dynamically changing a component’s `z-index` during animations can create an engaging effect. However, ensure that the animations don’t cause unexpected stacking conflicts.

Example shown below.






Heading

Because the image has a z-index of -1, it will be placed behind the text.

11. How to set border radius of a div for IE, FF & Chrome using CSS3?

CSS3 provides a new attribute border-radius to set round corner border. This works on IE. For Firefox & Chrome there are CSS hacks. In Firefox we have to use -moz-border-radius & in case of Chrome -webkit-border-radius. Look at the following CSS class.

.divBorderRadius
{
border-radius: 6px; -moz-border-radius: 6px; -webkit-border-radius: 6px;
}

12. What is clearfix hack in CSS?

When we apply float in elements locate inside a container that element doesn’t automatically force to adjust height. Once you declared float means it no longer available under a parent element. We can have 2 CSS hacks to fix this.

Before diving into the clearfix hack, it’s essential to understand what happens when we apply the float property to an element. When you float an element to the left or right, it is taken out of the normal document flow. This means that other elements do not adjust their position relative to the floated element. Consequently, the parent container that wraps the floated child may not recognize its height as those floated elements extend beyond its bounds.

clear:both; clearfix

Example of clearfix class

.clearfix {
display: inline-block;
}

.clearfix:after {
content: ".";
display: block;
clear: both;
visibility: hidden;
line-height: 0;
height: 0;
}

For alignment problems clearfix is a very useful hack in CSS.

13. What is Advanced CSS3 media queries?

In the way of responsive designing media queries act like a filter to CSS Styles. Using Media Queries we can change styles based on various Resolution & Devices. While declaring CSS with link tab media keyword helps to declare the type of media. Using media we can set min-width, max-width, min-height, max-height, orientation=portrait & orientation=landscape like attributes. Example of media queries are

Syntax to implement media query:

@media not|only mediatype and (media feature) {
//Your CSS Code Goes here...
}

Example of media query:

@media screen and (max-width: 600px) {
body {
background-color: #CCCCCC;
}
}

Advanced CSS3 media queries are an essential tool in the designer’s toolkit, enabling developers to create responsive layouts that adapt to the user’s device and preferences. By leveraging conditional styling based on various media features, designers can enhance usability and aesthetics, ultimately leading to a better overall experience for users. As web technology evolves, mastering media queries will continue to be a vital skill for anyone involved in web design and development. Whether you’re a seasoned developer or just starting, understanding how to effectively use media queries is crucial in today’s multi-device world.

14. What are the major CSS3 properties?

While designing a HTML page the major CSS properties we used are Background, Font, Text, Outline, Border, Margin, Padding, List, Table & Width.

The background property in CSS3 is incredibly versatile and allows designers to set the background color, image, and position of elements. The `background` shorthand property combines several background properties into one, including `background-color`, `background-image`, `background-repeat`, and `background-position`. This property ensures that the background complements the overall aesthetic of the webpage and enhances readability.

Font properties are crucial in determining how text appears on your webpage. CSS3 allows you to specify font family, size, weight, style, and line height. The `@font-face` rule also provides the ability to load custom fonts. This flexibility in typography ensures that the text matches the tone and character of the website, making it more engaging for users.

The outline property is a powerful tool for creating visual guidance around elements without affecting their layout. It is similar to borders but does not take up space. It can be styled with various attributes such as color, style, and width. This property is especially useful for accessibility, as it can help highlight selected elements or provide focus indicators.

15. What is the difference between Fixed Width Layouts & Liquid Layouts?

While designing a website if we fixed the web page width to a specific numerical value this is called Fixed width Layout. Fixed layout web pages are regardless about the client browser width.

Liquid layout is flexible depending upon the client browser. It is not a fixed width. Depending upon the client browser the web page will adjust automatically. Liquid layouts are always use percentage to adjust width. You can also say responsive UI designing is nothing but the advanced level of Liquid layout. Liquid layouts are more professional approach to web designing compare to fixed layout web pages.

16. Explain me the CSS Box Model.

The CSS3 box model is the rectangular area around the HTML elements. CSS3 Box Model consist of 4 different parts. Margin, Border, Padding & Content. Margin, Border & Padding can be declared using the following CSS3 syntax.

padding: 10px;
border: 5px solid gray;
margin: 0px;

Content Area

The innermost part of the box represents the actual content of the element—this includes text, images, or other types of media. The size of this area can be defined using properties like `width` and `height`. By controlling these dimensions, developers can ensure that their content is presented clearly and effectively on the webpage.

Padding

Surrounding the content area is the padding, which creates space between the content and the border of the box. Padding is transparent and can be customized for each side of the box (top, right, bottom, and left) using properties such as `padding-top`, `padding-right`, `padding-bottom`, and `padding-left`. A well-sized padding can enhance the readability of the content by providing breathing room, preventing text or images from appearing cramped against the borders.

Border

The border wraps around the padding (if any) and the content. It serves as a visual cue to clearly delineate the element from others. Borders can be styled in various ways—solid, dashed, dotted, and with different thicknesses and colors, using properties like `border-width`, `border-style`, and `border-color`. An appropriately styled border can add significant aesthetic appeal to a webpage.

Margin

Finally, the outermost layer is the margin, which is the space outside of the border. Margins are also transparent and can help separate elements from each other, thus contributing to overall layout organization. Similar to padding, margins can be defined for each side using `margin-top`, `margin-right`, `margin-bottom`, and `margin-left`. Setting proper margins is crucial for managing the spacing between elements and creating a balanced design.

Using CSS3 box model it helps to align the HTML elements.

17. What are CSS Variables, and how do they improve code maintainability?

CSS Variables, also known as Custom Properties, allow developers to define reusable values in stylesheets. They are declared using `–variable-name` and accessed via `var(–variable-name)`.

Conclusion

Mastering advanced CSS3 concepts like Flexbox, Grid, and performance optimization ensures efficient, maintainable stylesheets. Understanding these topics prepares candidates for modern front-end development challenges.

The post Frequently asked advanced CSS3 Interview Questions and Answers appeared first on OneStop Shop.

Advanced AngularJS Interview Questions with Answers

Nibedita Panda — Tue, 10 May 2016 17:11:38 +0000

Many newcomers has a question “What is AngularJS?”. In replay I can say AngularJS is a MVC framework to design web applications. It helps to enrich HTML for a great extend. Using AngularJS you can build structural & high performance based web applications. Directive is one of the most powerful feature in AngularJS. AngularJS comes with many in-built directives. Even you can Create your own. AngularJS is powered by Google. Due this is a newly introduced technology, there are lot of vacancies available for AngularJS developers. Are you one among them who is Seeking a Job in AngularJS. If so, before going to attained interview read our selected Angularjs Interview Questions.

What are the key features of AngularJS?

AngularJS is a latest technology introduced by Google. The key features of AngularJS are like Scope, Controller, View, Model, Directives, Validation, Filters, Data Binding, Services & Testable. AngularJS supports MVC & MVVM design pattern. Using AngularJS we can do massively Parallel Development. AngularJS Supports Single Page Applications design.

Does Angular use the JQuery library?

Yes. AngularJS is an advanced language. It supports JQuery library.

How to use ng-repeat in AngularJS?

Ng-repeat is a per-defined directive in AngularJS. Look at the Example below. Here I used ng-repeat to bind data from JavaScript. In sample data I have two fields name & designation. I am showing these records using ng-repeat in a HTML UL element.




 	{{emp.name}}{{emp.designation}}

How to use Filter in AngularJS?

Filter is like Search in AngularJS. In the following code I have 3 records & a search box. If I am doing search filter keyword help to purify the results according to the Query.




Search: 

 	{{emp.name}}
{{emp.designation}}

In AngularJS how will you initialize a select box with options on page load?

Using AngularJS ng-init directive. Look at the example below.



Name: 

You wrote: {{ empName }}

What are the advantages of using AngularJS?

AngularJS is a latest Technology introduced by Google. It has several advantages in web development. AngularJS supports MVC pattern. Using AngularJS we can do 2 ways data binding. AngularJS has per-defined form validations. AngularJS supports both client & server communication. AngularJS supports Animations.

How to use Controller in AngularJS?

Controller is a JavaScript constructor function. When Creating an application we need to provide initial value to the $Scope object of a Controller. We can add property to $Scope object. Before to create controller we have to create a module. Look at the example below how I created Controller in AngularJS.

var myApp = angular.module('myApp',[]);

myApp.controller('myController', ['$scope', function($scope) {
$scope.welcome = 'Hello!';
}]);

The property of a controller we can assign to the DOM object using ng-controller.


{{ welcome }}

What are the form Validations AngularJS provides?

Client Validations made easy using AngularJS. All input fields can have Required field, Minimum Length, Maximum Length, Matches a Pattern, Email, Number, URL & Custom Validations. Look at the Examples below.

Required Field Validation

Using Required field validation we can prevent form submission with null value. I mean input fields need to filled by the user. The syntax for required filed validation is as follows.

Minimum & Maximum field Length Validations

To prevent the input field from less or excess number of characters we use Minimum & Maximum length validation. The AngularJS directive used for Minimum & Maximum length validations are ng-minlength & ng-maxlength. Look at the example below.

Matches Pattern Validation

AngularJS provides ng-pattern directive to validate regular expressions. Look at the example below.

Email Validation

To valid an email id AngularJS provides ng-model directive. Using the following line of code we can validate an email id from any input field.

Number Validation

To validate an input against Number we can use ng-model directive from AngularJS. Look at the example below.

URL Validation

To validate an input field for URL we can use the following syntax in AngularJS.

How to create Directive using AngularJS?

Directives are designed to use as markers with DOM elements. Markers can be attribute, element name, comment or CSS class. AngularJS provides many in-built directives. Few of them are ngModel, ngView or ngBind. The naming standard directive follows is camel-case. Much like controllers directives are registered on Module. To register a directive we can use module.directive. The time we create directive by default it restricted to attribute. In order to create directive which will triggered by element or class name we need to use restrict. The options are as follows.

A – only matches attribute name
E – only matches element name
C – only matches class name

These restrictions can be combined as required.

AEC – it matches either attribute or element or class name

Let us look at the below example how to create a directive using AngularJS.

myAngularApp = angular.module("myAngularApp", []);

myAngularApp.directive('div', function() {
var directive = {};

directive.restrict = 'E'; /* using this we restrict this directive to elements */
directive.template = "My first directive: {{ EnterText }}";

return directive;
});

What is 2 way data binding in AngularJS?

In UI Development to create a template we basically do one way data binding. In case of Angular it is a MVC framework. Internally using one way data binding we merge template & model to display in view. But in 2 way data binding there is a continuous communication in between model & view. Where template is just pointing to the view.

What is the CDN link for AngularJS?

CDN is a permanent Global space where from we can access the various versions of library file to use directly in our web applications. For AngularJS you can refer the following CDN link.

https://ajax.googleapis.com/ajax/libs/angularjs/1.3.0-rc.0/angular.min.js

How to bind MySQL data to HTML5 using AngularJS?

In server end create a php file with MySQL query for the required data. Format it in the shape of JSON. Here I did this with the file name Customers_JSON.php.

Customers_JSON.php

[
{
"Name" : "Raghav Meheta",
"City" : "Berlin",
"Country" : "Germany"
},
{
"Name" : "Rakesh Srivastab",
"City" : "Lulea",
"Country" : "Sweden"
},
{
"Name" : "Biswabhusan Panda",
"City" : "Mexico D.F.",
"Country" : "Mexico"
},
{
"Name" : "Kumar Abhishek",
"City" : "Graz",
"Country" : "Austria"
},
{
"Name" : "Raveena Tondon",
"City" : "Madrid",
"Country" : "Spain"
}
]

in App.js create a angular module & controller. Inside the controller use $http.get method to fetch the data from JSON formatted php file. Look at the example below.

App.js

var myApp = angular.module('myApp', []);

myApp.controller('Controller', function($scope,$http) {
$http.get("Customers_JSON.php").success(function(response) {
$scope.names = response;
});
});

Finally, In your index.html file use ng-repeat over UL element to bind the response data. Sharing the code below.

Index.html


How to bind MySql data using AngularJS?




 	
{{ x.Name + ', ' + x.Country }}

How to use templateURL in the Directive of AngularJS?

To implement one line of HTML template is ok for Directive. If we are going to develop a more functional control depending upon HTML for a better professional approach we need to use templateURL. Look at the example below how I used a html page to display in side an AngularJS directive using templateURL.

index.html


Using templateURL in the Directive of AngularJS

app.js

var myApp = angular.module('myApp', []);

myApp.directive('templateUrl', function() {
return {
templateUrl: 'App-Template.htm'
};
});

App-Template.htm


This is a sample HTML file.

Is AngularJS supports MVVM with MVC?

Yes. AngularJS is an Advanced JavaScript framework. It supports both MVVM & MVC design patterns.

What is routes in AngularJS?

In web development single page application designing is more popular than multi page application designing. Let us assume you have 3 pages in your application mainpage, aboutus & contactus. Using older standard of web development you created 3 html pages mainpage.html, aboutus.html & contactus.html. Depending upon the user requests you are redirecting the user to the respective html page. As an framework designer think for a while if we can keep a container or view in main page where you can display the respective pages depending upon the user request, is not this is a better approach to classical web development. AngularJS Routing & Views did the same. Using Routing & Views in AngularJS you can easily create single page web application with no page refresh on a new page redirect. To achieve this technique ng-view is act like the container & routing helps to load each page in the ng-view depending upon the user request. The shape of request is like the url /mainpage or /aboutus. To have a demo in AngularJS Routing Look at the Example.

What is the difference between compile & link functions in angularjs?

Compile function used for Template DOM manipulation. Hence manipulations that apply to all DOM clones of the template associated with the directive.

Link function used for registering DOM listeners. A $watch() function allows a directive to be notified of instance scope property changes, which allows the directive to render an updated instance value to the DOM by copying content from the instance scope into the DOM.

What is difference between Service & Factory?

Factory allows us to add some logic before creating the object we require. It differs from service in a way where it allows us to pass the function which factory then invokes & returns the result. To create factory we use module.factory(‘factoryName’, function); & for service we use module.service(‘serviceName’, function);. If you’re using an object, you could use the factory provider. If you’re using a class you could use the service provider.

What is the difference between ng-if and ng-show/ng-hide?

ng-show or ng-hide inserts DOM element and show/hide depending upon condition. While ng-if check condition before inserting DOM element. ng-if is more faster then ng-show/ng-hide. When we needed the DOM to be loaded conditionally, ng-if is a best choice.

N.B. I Collected the above AngularJS Interview Questions from various interviewers. Hope if you are prepared well with the above Questions you will must fetch similar questions during your interview. Best of Luck!

The post Advanced AngularJS Interview Questions with Answers appeared first on OneStop Shop.

Top Interview Questions by Interviewers for Job Seekers

Data Science Interview Questions with Answers for Freshers

Key Components of Data Science

Key Techniques in Data Science

Popular Tools and Technologies

Applications of Data Science

Challenges in Data Science

1. What is the difference between supervised and unmanaged machine learning?

2. Explain how a ROC curve works?

3. What is selection Bias?

4. Explain the SVM machine learning algorithm in detail

5. What are the support vectors in SVM?

6. What are the functions of the different kernels in SVM?

7. Explain in detail about the Decision Tree algorithm

8. What is deep learning?

9. What is reinforcement learning?

10. What is selection bias?

11. Explain what regularisation is and why it is useful

12. What is TF/IDF vectorization?

13. What are Recommender Systems?

14. What is the difference between regression and classification of ML methods?

15. What is ‘Naive’ in a Naive Bayes?

16. Why do we generally use Softmax nonlinearity function as the last operation in-network?

17. You are given a data set consisting of variables with more than 30 per cent missing values. How will you deal with them?

18. For the given points, how will you calculate the Euclidean distance in Python?

19. What are recommender systems?

20. How do you find RMSE and MSE in a linear regression model?

21. How can you select k fork-means?

22. What is the significance of p-value?

23. How can outlier values be treated?

24. How can a time-series data be declared as stationery?

25. How can you calculate accuracy using a confusion matrix?

Basic SEO Interview Questions & Answers for Freshers

Difference between Organic & Referral traffics?

Is meta keywords & description matters?

What is keyword density?

Why my blog required a robots.txt file?

What is a Sitemap?

Do I required both the Sitemap (HTML & XML) in my blog?

What is the difference between Indexing & Crawling?

How can I know how many pages are indexed in Google or Bing?

What are Google Webmaster tools?

How to index a link quicker in Google?

Is image optimization effects in SEO?

How to Choose a page title?

How do I test is my pages are Mobile Friendly?

How long it takes to see SEO in results?

How many days Google take to index?

Is manual link building good for indexing?

What is the benefit of using H1, .. H6 or Bold letters with Content?

Do I submit my blog to both the popular Search Engines Google and Bing?

How much time Bing takes to Crawl?

What is the difference between On-page and Off-page SEO?

Do I will do link sharing in Social medias?

Is Competitor analysis helps in SEO?

What is Search Engine submission and how it is useful in SEO?

Do I will crate a Wikipedia page for my blog?

Is I required to Track user activities?

What is Google Analytics?

What is a inbound link?

UI Developer Interview Questions for Experienced Professionals

HTML5 Interview Questions

CSS3 & BootStrap UI Developer Interview Questions

JAVASCRIPT Interview Questions

JQUERY Interview Questions

ANGULARJS Interview Questions for UI Developer

SQL Server Interview Questions for DBA professionals

What is Clustered & Non-Clustered Index in SQL?

What is the Difference between Truncate and Delete?

What Primary key and Unique key?

How to change Database name in SQL Server?

How to Display current date using SQL Query?

How can we delete duplicate records from a table with no primary key?

Microsoft ASP.NET Interview Questions with Answers

What is the difference between Classic ASP & ASP.NET?

What are the different types of validation provided by ASP.NET?

What are the types of Authentication in ASP.NET?

What is view state?

What are the state management technique implemented by ASP.NET?

Explain me the use of Global.asax