Top 100 jQuery Interview Questions and Answers in %currentyear%

JQuery is the JavaScript library that is designed to simplify HTML DOM tree manipulation and traversal, as well as event handling, Ajax, and CSS animation. It is the free, open-source software that uses the permissive MIT License. 

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What is the purpose of jQuery?

The main purpose of jQuery is to make it easier to use JavaScript on the website. jQuery will usually take a lot of common tasks that will require many lines of JavaScript code in order to accomplish and wrap them into methods that we call with a single line of code.

If you are looking for the most frequently asked jQuery Interview questions and answers, then you are on the right page. We have listed the most commonly asked jQuery Interview Questions and Answers. Make sure you go through the entire post so that you will not miss any jQuery questions.

Top jQuery Interview Questions and Answers

1. Define jQuery?

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JQuery is the JavaScript library that is designed to simplify HTML DOM tree manipulation and traversal, as well as event handling, Ajax, and CSS animation.

2. List some of the advantages of jQuery?

  1. Ease of use: It is easier to use when compared to the standard javascript and other libraries.
  2. It has the ability to keep the code clear, simple, readable, and reusable.
  3.  Large library: It has a lot of functions when compared to javascript.
  4. Great documentation and tutorials: the jQuery website has a lot of tutorials that are required for beginners.
  5. It has JavaScript enhancement without the overhead of learning new syntaxes.
  6. Ajax support: It lets us develop the templates easily.

3. Define jQuery selectors?

jQuery selectors will allow us to select and manipulate HTML elements. We use the jQuery selectors to find or select the  HTML elements that are based on the id, name, types, classes,  attributes, values of attributes, and many more. It is usually based on the existing CSS Selectors, and it has some custom selectors also.

4. Is jQuery a programming language?

jQuery is not a programming language; instead, we can say it is a cross-platform JavaScript library. There are many JavaScript libraries available such as MooTools, Knockout, or Angular, and jQuery is one of the most popular among them.

5. Is jQuery a JavaScript or a JSON library file?

We can say that jQuery is a library of JavaScript files, and it contains DOM event effects and Ajax functions.

6. Whether jQuery HTML work for HTML and XML documents?

No, the jQuery HTML works only for HTML documents, and not for XML Documents.

7. Differentiate between JavaScript and jQuery?

JavaScript is a language for programming.It is a JavaScript library, a framework that will help us to use JavaScript to simplify common web tasks.
Here, we have to write an extra code or move around to have cross-browser compatibility.It has an inbuilt feature of cross-browser compatibility.
It is verbose as one has to write own scripting code, which is often time-consuming.It is concise, and there is no need to write much code as scripting already exists.

8. Can we say that jQuery is a replacement for JavaScript?

Since jQuery is only a library of JavaScript, it cannot replace JavaScript. All the jQuery code is JavaScript, but jQuery does not include all the JavaScript code.  jQuery is only optimized to do common scripting functions with lesser lines of code.

9. Name some of the jQuery functions used to provide effects?

animate()It runs a custom animation on the selected elements.
delay()It will set a delay for all the queued functions on the selected elements.
clearQueue()It will remove all the remaining queued functions from selected elements.
deQueue()It removes the next function from the queue and will then executes the function.
fadeOut()Fades out the selected elements
fadeIn()Fades in the selected elements.
stop()It stops the currently running animation for selected elements.
toggle()It toggles between hide() and show() methods.
show()Shows the selected elements
hide()Hides the selected elements

jQuery Interview Questions and Answers

10. Can you differentiate between .empty(), .remove() and, .detach() in jQuery?

empty():  It removes all the content and the child elements from the selected element. This method will not remove the selected elements.

detach(): It removes all child elements with the selected elements. However, it keeps all the data and the event handlers of the removed elements. This method is only preferred when we want to remove elements but to keep a copy of the removed elements, which can be reused later.

remove():  It removes all child elements with the selected element. In this method, one can restore all the data but not the event handlers of the removed elements from DOM. All data and events related to elements will be removed.

11. Why do we use jQuery?

  1. It improves the performance of an application.
  2. It will facilitate you to write minimal lines of code for the UI-related functions.
  3. jQuery is very easy to learn and use.
  4. It is very fast and extensible.
  5. It provides cross-browser support.

12. Why do we use CSS() method in jQuery?

The CSS() method in jQuery is used to set or return one or more style properties for selected elements. When it is used to return the properties: This method will return the specified CSS property value of FIRST matched elements.

13. What are the different ajax methods available in jQuery?

$.ajax()It performs an async AJAX request.
$.get()It Loads the data from a server using the AJAX HTTP GET request.
$.getScript()It loads and executes JavaScript from a server using the AJAX HTTP GET request.
$.post()It loads the data from a server using the AJAX HTTP POST request.
ajaxError()It will specify a function to run when an AJAX request completes with an error.
ajaxStart()It will specify a function to run when the first AJAX request initiates.
ajaxComplete()It will specify a function to run when the AJAX request gets completed.
load()It loads the data from the server and puts the returned data back into the selected element.

14. Define $() in jQuery library?

In JS, $ is commonly used as a selector function. In jQuery, the $ function does more than just select things, though. One can pass it to a selector to get the collection of matched elements from the DOM. One can pass it as a string of HTML to turn into the DOM element, which can then inject into the document.


$(document).ready(function() {  
$("p").css("background-color", "white");  

15. Define events in jQuery?

In jQuery, the events are the actions that are detected by the web application. They are mainly used to create dynamic web pages. An event will show the exact moment when something happens—examples of events: A mouse click.

16. Name the compatible operating systems with jQuery?

  1. Linux
  2. Windows
  3. Mac

17. Why do we use the toggle() method in jQuery?

The toggle() method in jQuery attaches two or multiple functions to toggle between for the click event for selected elements. When we click on an element, the first specified function fires, next when we click again, the second function fires, and so on. 

18. What is the importance of jQuery.length?

The length property of the jQuery is used to count the number of elements present in the jQuery object. The size() function will also return the number of elements in the jQuery object.

19. How to include the jQuery library in the ASP.Net project?

  1. First, download the jQuery library from
  2. Include that reference on the page.

jQuery Interview Questions and Answers

20. Syntax for fadeToggle() method in JQuery?

The jQuery fadeToggle() method is mainly used to toggle between fadeIn() and fadeOut() methods. If the elements are faded in, then it makes them faded out, and if they are faded out, then it makes them faded in.


$(selector).fadeToggle(speed, easing, callback);

21. Define jQuery click event?

The click event usually occurs when an element is clicked. The click() method will trigger the click event, or it will attach a function to run when the click event occurs.


  //This code is specified to  run when the click event is triggered

22. Explain bind() vs live() vs delegate() methods in jQuery?

The jQuery.bind() method will register event type and an event handler directly to a DOM element.

The live() method will attach the event handler to the root level of a document along with the associated selector and event information. This also responds to the events that are generated by dynamically added elements.

jQuery.delegate() method behaves in a same way as that of the  .live() method. But, here, instead of attaching the event information or selector to the document, one can choose where it is anchored. This means that you can control on which node the events will be added.

23. What do we use the delay() method in JQuery?

The delay() method is mainly used to delay the execution of functions in a queue. It is mainly used to make a delay between the queued jQuery effects. The jQUery delay () method will set a timer to delay the execution of the next item in a queue.


$(selector).delay (speed, queueName)

24. Explain jQuery each() function?

We mainly use jQuery’s each() function to loop through each element of the target jQuery object( an object that contains one or multiple DOM elements and it exposes all the jQuery functions). It is useful for multi-element DOM manipulation and iterating over arbitrary arrays and object properties.

25. Can you write down the command that gives the version of jQuery?

The command $.ui.version is used to return jQuery UI version.

26. Why do we use HTML() method in JQuery?

In jQuery, the HTML() Method is used to set or return the inner HTML content of selected elements. It will return the content of the first matched element. It sets the content of the matched element.

27. Can you list the types of selectors in jQuery?

  1. #ID: It is mainly used to select a single element that matches the specific ID.
  2. Name: It is used to select all the elements that match the element name.
  3. Attribute selector: It is used to select the elements based on their attribute value.
  4. Universal(*): It is used to select all the elements that are available in the DOM
  5. Multiple Elements E, F, G: They are used to select the combined results of the selectors E, F, or G.

28. Define jQuery connect? 

The jQuery “connect” can be defined as a plugin used to bind or connect a function to another function. It will execute a function when the function from another object is executed. It is the same as assigning the handler for another function. With the help of “connect,” we can bind more than one function.

29. Is jQuery library a server scripting or client scripting?

jQuery is a library for client-side Scripting.

30. Can you tell us how CSS classes can be manipulated in HTML by using jQuery?

The jQuery CSS method will allow us to manipulate the CSS class or style properties of the DOM elements. The Query will provide several methods to manipulate CSS classes that are assigned to HTML elements.

The most significant methods are addClass(), removeClass() and toggleClass().

addClass(): This method is used to adds one or multiple classes to the selected elements.



To add multiple classes, use the below syntax:


$(selector).addClass(class1, class2);

removeClass():  It is used to remove a single class, or multiple classes, or all the classes from the specified elements.

Syntax to remove single class:


Syntax to remove multiple classes:

$ (selector).removeClass(class1, class2, class 3);

Syntax to remove all classes at one shot:


toggleClass():  It toggles between adding or removing classes to the given elements.



jQuery Interview Questions and Answers

31. How to use JQuery connect?

To use “connect”:

  1. You have to download the jQuery connect file from
  2. Then, you need to include that file in the HTML file.
  3. Now, use $.connect function to connect the function to another function.

32. Define jQuery UI Autocomplete?

Auto-completion is a technique that is frequently used in modern websites to provide users with a list of suggestions for the starting of the word, where he or she has typed in the text box. The user can now select an item from the list, which is displayed in the input field.

33. How can one perform jQuery Ajax requests?

jQuery provides the ajax() method in order to perform the  AJAX, i.e., asynchronous HTTP request.


$.ajax({name:value, name:value, ... })

The parameters specify one or more value of name-value pairs.

CacheA function to run before the request is sent.
complete(xhr,status)A function that is used to run when the request is finished, i.e., after success and error functions)
contextIt specifies “this” value for all the AJAX-related callback functions.
dataFilter(data,type)A function to handle the raw response data of XMLHttpRequest.
ifModifiedIt is a Boolean value that specifies whether a request is successful only if the response has changed since the last request. The Default value is: false.
error(xhr,status,error)It is a function to run if the request fails.
URLIt specifies the URL to send the request to. The Default value is the current page.

34. Why do we use the parm() method in jQuery?

The jQuery param() method is mainly used to create the serialized representation of the object.

35. What is the initial point of code execution in jQuery?

The starting point of jQuery code is $(document).ready() function. It will be executed when the DOM gets loaded.

36. Differentiate between jQuery.get() and jQuery.ajax()?

The get() is a specialization to ajax just to get some data.The ajax() method is more robust and configurable; it allows us to specify how long to wait and how to handle an error.

37. Differentiate between $(this) and this in jQuery?

The $(this) is a jquery wrapper around the same.The “this”  is the DOM object.
When we are using $(this), we can call jQuery methods on it, but not the DOM methods.When we are using this, we can call DOM methods on it, but not the jQuery methods. 

38. What is the most basic requirement to start with jQuery?

One has to refer to its library to start a jQuery. One can download the latest version of jQuery from the website

39. Write a jQuery code selector that is used for querying all the elements whose ID ends with the string “IB”?


40. Can you tell us in what scenarios jQuery is used?

  1. Apply CSS static or dynamic
  2. Mainly for Animation effects
  3. Calling functions on events
  4. Manipulation purpose

jQuery Interview Questions and Answers

41. Can we use any other name in place of $ in jQuery?

Instead of $  you can use jQuery as a function name. For example:

jQuery(document).ready(function() {    
jQuery("p").css("background-color", "white");    

42. Define .promise() method in jQuery?

The promise() method in jQuery is used to return a dynamically generated promise that is resolved when all the actions of a certain type are bound to the collection, queued or not, have ended.

43. Is it possible to use multiple document.ready() function on the same page?

Yes. We can use any number of document.ready() function on same page.


$(document).ready(function() {    
$("h1").css("background-color", "white");    
$(document).ready(function() {    
$("p").css("background-color", "black");    

44. Differentiate between prop() and attr()s?

The prop() and attr() are both used to get or set the value of the specified property of the element attribute. But the major difference is:

The prop() will return its current value.The attr() will give the default value of a property.

45. Differentiate between find and children methods?

This method is used to find all the descendant elements of selected elements.This method is used to find all the children elements that are related to that selected element.

46. Define CDN?

A content delivery network(CDN), or content distribution network, is defined as a geographically distributed network of the proxy server and their respective data centers. The main aim is to provide high performance and availability by distributing the service spatially relative to the end-users.

47. How can we read, write and delete cookies in jQuery?

We can deal with cookies in jquery by using the Dough cookie plugin. The dough is easy to use and has robust features.

Create cookie: $.dough(“cookie_name”, “cookie_value”);

Read Cookie: $.dough(“cookie_name”);

Delete cookie: $.dough(“cookie_name”, “remove”);

48. List the advantages of using CDN?

  1. Your reliability and response times get a huge boost
  2. A CDN enables global reach
  3. A CDN saves a lot of money
  4. 100% percent availability
  5. Decrease server load
  6. 24/7 customer support
  7. Increase in the number of Concurrent Users
  8. DDoS protection

49. What is the goal of CDN?

The main aim of the CDN is to provide content to the end-users with high performance and high availability.

jQuery Interview Questions and Answers

50. List few features of jQuery?

  1. HTML manipulation
  2. DOM manipulation
  3. DOM element selection
  4. CSS manipulation
  5. Effects and Animations
  6. Utilities
  7. AJAX
  8. HTML event methods

51. List the features of jQuery which are used in web applications?

jQuery uses features like 

  1. Sliding
  2. File uploading
  3. Accordion in web applications

52. How to use a jQuery library in your project?

We can use the jQuery library in the ASP.Net project by downloading the latest jQuery library from the website that will include the references to the jQuery library file in the HTML/PHP/JSP/aspx page.

<script src="_scripts/jQuery-1.2.6.js" type="text/javascript"></script>   
<script language="javascript">   
$(document).ready(function() {   

53. List the different types of selectors in jQuery?

  1. CSS Selector
  2. Custom Selector
  3. XPath Selector

54. What is the jQuery filter?

When given a jQuery object that will represent a set of DOM elements, the filter() method will construct a new jQuery object from the subset of matching elements. The supplied selector is now tested against each element; all the elements that are matching the selector will be included in the given result.

55. What is the “serialize() “method in JQuery?

We use the jQuery serialize() method to create a text string in standard URL-encoded notation. It is mainly used in form controls such as <input>, <textarea>, <select> etc. It will serialize the form values so that its serialized values are used in the URL query string while making an AJAX request.

56. How can we add and remove CSS classes to an element using jQuery?

We use addclass() jQuery method to add CSS class to the element.

Example: (A small snippet of code is given below to add a class)


We use removeclass() jQuery method to remove a CSS class from the element.

Example:( a small snippet of code to remove class is given below)


57. Why do we use val() method in JQuery?

The val() method in jQuery is mainly used to get the values of the form elements. This method does not accept any arguments. This method will return a NULL when no option is selected, and in the case of one or more selections, it returns an array that contains the value of each selected option.



58. Will you write a jQuery code to select all the links inside the paragraph?

<!DOCTYPE html>    
 <title>jQuery Example</title>    
 <script type="text/javascript" language="javascript">    
    $("p a").attr("href", "");  
    <p><a>Learn JavaScript</a></p>  
    <p><a>Learn jQuery</a></p>   

59. Can you name the two types of CDNs?

There are two types of CDN:

  1. Google: It loads the jQuery from Google libraries API.
  2. Microsoft: It loads the jQuery from AJAX CDN.

60. How to disable jQuery animation?

To globally disable the animation using jQuery, you have to use jQuery. fx. off() method.

61. Why do we use the animate() method in jQuery?

We use the animate function to apply a custom animation effect to elements. 


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


  1. “param”  represents the CSS properties where you want to apply the animation.
  2. “duration” specifies how long the animation can run. It can be one of the following values:  “fast,” “slow,” “fast,” “normal,” or milliseconds.
  3. easing” represents a string that specifies the function for the transition.
  4. The callback” here, is the function where we want to run once the animation effect gets completed.

62. What is jQuery Ajax?

AJAX (Asynchronous JavaScript and XML) is a  technology that helps us to load the data from the server without refreshing a browser page. JQuery is a tool that provides a rich set of AJAX methods to develop the next-generation web application.

63. What is the use of the ajax method load() do?

The ajax load() method will load the data from the server and puts the returned data back into the selected element.

64. List the categories in jquery Events?

The DOM events are as follows:

  1. Form
  2. Keyboard
  3. Mouse
  4. Browser
  5. Document Loading

65. What are the benefits of jQuery Ajax methods?

  1. Cross-browser support
  2. Simple methods to use
  3. The ability to send the requests like “GET” and “POST.”
  4. Ability to Load XML, XML, HTML or Scripts

66. Differentiate between onload() and document.ready() methods?

The Body.Onload() event is called only after DOM, and associated resources such as images get loaded.The jQuery’s document.ready() event is called once DOM is loaded, and it will not wait for the resources like images to be loaded.

67. Is jQuery necessary for Bootstrap?

The Bootstrap will use jQuery for JavaScript plugins such as models, tooltips, etc. But, if only the CSS part of Bootstrap is used, then you don’t need jQuery.

68. Can you differentiate between jquery.min.js and jquery.js?

The min. js is nothing else but the compressed version of jquery.jQuery.js is pretty and easy to read.
.min removes all unnecessary characters in order to make the file size smaller.It does not remove unnecessary characters.

69. Define JQuery.noConflict?

The jQuery no-conflict is an option that is given by jQuery to overcome the conflicts between the various js frameworks or libraries. If we are using the jQuery no-conflict mode, then it means that we are replacing $ with a new variable, and we are assigning it to jQuery some other JavaScript libraries.

70. What is jQuery Mobile?

jQuery Interview Questions - jQuery mobile

jQuery Mobile can be defined as a touch-optimized web framework, that is, more specifically, a JavaScript library, and it is developed by the jQuery project team.

71. Define jQuery UI?

jQuery UI can be defined as a curated set of user interface(UI) interactions, effects, widgets, and themes that are built on the top of a jQuery JavaScript Library. If you want to build a highly interactive web application or you just have to add a date picker to a form control, the jQuery UI is a perfect choice.

72. How to use jQuery in ASP.NET?

As we know, jQuery is a lightweight, fast JavaScript library and is CSS3 compliant, and supports multiple browsers. The jQuery framework is expandable and handles the DOM manipulations, AJAX, CSS, Events, and Animations.

73. Define Data Table plug-in for jQuery?

DataTables is a plug-in for a jQuery Javascript library. It is a very high flexible tool that is built upon the foundations of the progressive enhancement that will add advanced features to any HTML table.

74. How to use the hide() method on a button click using jQuery?

By using this hide () method, we can hide the HTML elements. 

75. What is Qunit?

QUnit can be defined as a unit testing framework for the JavaScript programming language. Qunit is important in the field of test-driven development, and it is used by jQuery UI, jQuery, and jQuery Mobile projects. The Qunit is capable of testing any generic JavaScript codebase.

76. Differentiate between the .detach() and remove() methods in jQuery?

This method retains all the jQuery data that is associated with the removed elements..remove() method is useful when removed elements need to be reinserted into the DOM later.

77. How can you handle the Controls attribute Using jQuery?

To handle the Controls attribute  jQuery uses .addClass(), .removeClass(), .css(), .toggleClass(), etc to manage all  the html and css attributes of any html control.

78. Can you list the four parameters used for the jQuery Ajax method?

The four parameters are mentioned below:

  1. URL: URL for sending the request
  2. Success:  It specifies a callback function when the request is successful
  3. Type: GET/POST request
  4. DataType: It returns the  data type – HTML, XML, text etc.

79. Define jQuery Datepicker?

The datepicker is usually tied to a standard form input field. Focus on the input to open an interactive calendar in a small overlay. Now choose a date, then click elsewhere on the page, or hit the Esc key to close. If we choose the date, feedback is shown as the input’s value.

80. What is slideToggle() effect?

It is mainly used to toggle between the sliding up and sliding down for selected elements.

81. Define bind() and unbind elements in jQuery?

The jQuery bind() method will attach an event handler to elements.

The unbind() detaches an existing event handler from the elements.

82. Define jQuery plugins?

A jQuery plugin is a new method that is used to extend jQuery’s prototype object. By extending the prototype object, we can enable all the jQuery objects to inherit the methods that we add. We can make our own plugins, and we can use them privately in the code, or we can release them into the wild.

83. Why do we use the fade toggle() method in JQuery?

We mainly use it to toggle between the fadeIn() and fadeOut() functions. 

84. How to use an array with jQuery?

To create an array we use $.makeArray(<object>)

To search for a specific element in array using $.inArray use the below syntax:

$.inArray(“Jack”, myArr);

To merge two arrays, we use the $.merge() method


var arr1 = [“A”, “B”, “C”, “D”];

var arr2 = [“W”, “X”, “Y”, “Z”];

var mergeArr = $.merge(arr1, arr2);

85. Can you tell the Differences between Map and Grep function in jQuery?

The map function will translate a set of elements into another set of values in the jQuery array that (may have or may not have) elements.Grep is used to find an element in an array.
$(“<element>”).map(<function to execute for elements in the object>)jQuery.grep(myArr, function(){}

86. List the filters supported by the jQuery filter?

Few of the filters supported by jQuery are listed below:

  1. .eq()
  2. .first()
  3. .last()
  4. .filter()
  5. .has()
  6. .not()

87. Define method chaining in jQuery, and what are the advantages?

JQuery is providing another robust feature known as method chaining that will allow you to perform many actions on the same set of elements, that too, all within a single line of code. It is possible because most of the jQuery methods will return a jQuery object that is further used to call another method.

88. Define attribute in jQuery?

There are important properties of DOM or HTML elements like the <img> tag, the src, class, id, title, and other properties. These are known as attributes.

Most of the attributes are available through JavaScript as the DOM node properties. Some of the common properties are:

  1. className
  2. tagName
  3. id
  4. href
  5. title
  6. rel
  7. src

89. How to find browser and browser version in jQuery?

Using the $.browser property of the jQuery returns the browser information.

90. Define jQuery.holdReady() function?

The holdReady() method of the jQuery will allow the caller to delay the jQuery’s ready event. This method has to be called early in the document, like in the <head> section immediately after the jQuery script tag. By calling this method after the ready event that has already fired will have no effect. In order to delay the ready event, first, you need to call $.

91. Why do we use Draggable, Droppable, Resizable, Selectable in jQuery UI?

Draggable: It will enable the draggable functionality on any DOM element. 

Droppable: It will enable any DOM element to be droppable, a target for the draggable elements.

Resizable: It will enable any DOM element to be resizable. With the cursor, you have to grab the right or bottom border and drag it to the desired width or height.

Selectable: It will enable a DOM element to be selectable. Draw a box with the cursor to select items. Now hold down the Ctrl key to make various non-adjacent selections.

Sortable: It will enable a group of DOM elements to be sortable.  

92. Define slice() method in jQuery?

This slice() method is used to select a subset of the matched elements by giving the range of indices. In simple words, it gives a set of DOM elements on the basis of its parameters, i.e.,  (start, end).

Apart from technical questions, you have to prepare for some general and scenario-based questions, where you need to answer them based on your experience. I have noted below a few of the questions. Please go through them as well.

93. Why should we hire you?

94. Tell us what you know about our company?

95. What is your salary expectation?

96. What are your strengths?

97. Why do you think you fit into this role?

98. Where do you want to see yourself after five years?

99. Tell us how you can play the role of a Team Leader?

100. Tell me something about yourself?

Thank you for spending your time on this post. You can also check our Node.Js Interview Questions.

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