Top 50 Best JQuery Interview Questions 2024 (Freshers/Experienced)

Jquery Interview Questions And Answers

Q1.What is jQuery?

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jQuery is a feature-rich JavaScript library that makes HTML document traversal and manipulation, event handling, animation, and Ajax much simpler and faster. jQuery has an easy-to-use API that works across many browsers. UI related functions can be written with minimal lines of code using jQuery.

Q2.What is the difference between JavaScript and jQuery?

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JavaScript is an interpreted programming language whereas jQuery is a library with APIs built for JavaScript. jQuery simplifies the use of the JavaScript language.

Q3.What are the effects methods used in jQuery?

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jQuery enables us to add effects on a web page. jQuery effects can be categorized into fading, sliding, hiding/showing and animation effects. jQuery provides many methods for effects on a web page

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These are the effects methods used in jQuery:

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show() – It displays or shows the selected elements.

hide() – It hides the matched or selected elements.

toggle() – It shows or hides the matched elements. In other words, it toggles between the hide() and show() methods.

fadeIn() – It shows the matched elements by fading it to opaque. In other words, it fades in the selected elements.

fadeOut() – It shows the matched elements by fading it to transparent. In other words, it fades out the selected elements.

Q4.What is jQuery Ajax?

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AJAX is an acronym standing for Asynchronous JavaScript and XML and this technology helps us to load data and exchange data with the server without a browser page refresh. JQuery is a great tool which provides a rich set of AJAX methods to develop next-generation web applications.

Q5.What does ajax() method do?

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This method sends an asynchronous http request to the server.

Q6.What does the ajax method load() do?

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The load() method sends an http request to load the html or text content from the server and adds them to the DOM element(s).

Q7.What are the jQuery Ajax Events?

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The jQuery library also includes events which will be fired based on the state  of the Ajax request, these are called Ajax events.

Q8.What does the jQuery Ajax event method ajaxComplete() do ?

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Whenever an Ajax request completes, jQuery triggers the ajaxComplete  event. Any and all handlers that have been registered with the .ajaxComplete() method are executed at this time.

Q9.What does the jQuery ajax event method ajaxStart() do?

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Whenever an Ajax request is about to be sent, jQuery checks whether there are any other outstanding Ajax requests. If none are in progress, jQuery triggers the ajaxStart  event. Any and all handlers that have been registered with the .ajaxStart() method are executed at this time.

Q10.What are Events in jQuery?

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Responding to user actions on a webpage is called events. jQuery provides simple methods for attaching event handlers to selections. When an event occurs, the provided function is executed.

Q11.What are the categories in jquery Events?

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The common DOM events are as follows:

Form

Keyboard

Mouse

Browser

Document Loading

Q12.What is the use of css() method in JQuery?

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The jQuery CSS() method is used to get (return)or set style properties or values for selected elements. It facilitates you to get one or more style properties.

Q13.What is the difference between find and children methods?

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Both the methods are used to filter the child of the matched elements. Find method is used to find all levels down the DOM tree but children method searches only a single level down the DOM tree.

Q14.What are the selectors in jQuery and what are the types of Selectors?

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If you would like to work with an element on the web page, first you need to find or select it. Selectors find the HTML elements using jQuery.

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There are many types of selectors in the jQuery library. Some basic selectors are:

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Name: It is used to select all elements which match with the given element Name.

#ID: It is used to select a single element which matches with the given ID

.Class: It is used to select all elements which match with the given Class.

Universal (*): It is used to select all elements available in a DOM.

Multiple Elements E, F, G: It is used to select the combined results of all the specified selectors E, F or G.

Attribute Selector: It is used to select elements based on its attribute value.

Q15.What is the difference between the ID selector and class selector in jQuery?

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ID selector and class selector are the same as they are in CSS. ID selector uses ID while the class selector uses a class to select elements. You use an ID selector to select just one element. If you want to select a group of elements, having the same CSS class, you can use the class selector.

Jquery Questions

Q16.What are the Advantages of jQuery Ajax methods?

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The advantages of using jQuery Ajax methods are

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Cross-browser support

Simple methods to use

Ability to send GET and POST requests

Ability to Load JSON, XML, HTML or Scripts

Q17.What is the difference between onload() and document.ready() methods?

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

Q18.What is jQuery connect?

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A ‘ jQuery connect’ is a plug-in used to connect or bind a function with another function. Connect is used to execute a function whenever a function from another object or plug-in is executed.

Q19.Is jQuery required for bootstrap?

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Bootstrap uses jQuery for JavaScript plugins (like models, tooltips, etc). However, if you just use the CSS part of Bootstrap, you don’t need jQuery.

Q20.What is jQuery Mobile?

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jQuery Mobile is an HTML5-based user interface system designed to make responsive web sites and apps that are accessible on all smartphones, tablet and desktop devices.

Q21.What is the difference between jquery.min.js and jquery.js?

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jquery.min.js is a compressed version of jquery.js(whitespaces and comments are removed, shorter variable names are used and so on) in order to preserve bandwidth. In terms of functionality, they are absolutely the same. It is recommended to use this compressed version in the production environment. The efficiency of web page increases when the minimized version of jQuery is used.

Q22.Is it possible that jQuery HTML works for both HTML and XML documents?

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No, jQuery HTML only works for HTML documents. It doesn’t work for XML documents.

Q23.What is jQuery UI?

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jQuery UI is a set of user interface interactions, effects, widgets, and themes built on top of the jQuery JavaScript Library. jQuery UI works well for highly interactive web applications with many controls or for a simple page with a date picker control.

Q24.What is a Data Table plug-in for jQuery?

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DataTables is a plug-in for the jQuery Javascript library. It is a highly flexible tool, built upon the foundations of progressive enhancement, which adds advanced features to any HTML table.

Q25.What is Qunit?

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QUnit is a powerful, easy-to-use JavaScript unit testing framework. It’s used by the jQuery, jQuery UI, and jQuery Mobile projects and is capable of testing any generic JavaScript code.

Jquery Interview Questions 2020

Q26.Which sign is used as a shortcut for jQuery?

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Dollar ($) sign is used as a shortcut for jQuery.

Q27.Is jQuery is a client or server scripting?

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jQuery is a client scripting.

Q28.What is the script build up by jQuery?

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jQuery is a Javascript file and it is single javascript file that contains common DOM, event effects and Ajax functions.

Q29.How can we debug jQuery?

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There are two ways to debug jQuery:

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Debugger keyword

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Add the debugger to the line from where we have to start debugging and then run Visual Studio in Debug mode with F5 function key.

Insert a break point after attaching the process

Q30.What are all the ways to include jQuery in a page?

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Following are the ways to include jQuery in a page:

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Local copy inside script tag

Remote copy of jQuery.com

Remote copy of Ajax API

Local copy of script manager control

Embedded script using client script object

Q31.What is the use of jQuery.ajax method ()?

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jQuery.ajax method is used for asynchronous HTTP requests.

Q32.Where can we download JQuery?

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jQuery javascript can be downloaded from jQuery official website – www.jquery.com

Q33.Is jQuery is a replacement of JavaScript?

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No, jQuery is not a replacement of JavaScript.

Q34.What is called chaining?

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Chaining is used to connect multiple events and functions in a selector.

Q35.What are the advantages of jQuery?

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Following are the advantages of jQuery:

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Just a JavaScript enhancement

Coding is simple, clear, reusable

Removal of writing more complex conditions and loops

Q36.Whether C# code behind can be called from jQuery?

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Yes, we can call C# code behind from jQuery.

Q37.What is the use of jQuery.data() method?

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jQuery data method is used to associate data with DOM nodes and JavaScript objects. This method will make a code very concise and neat.

Q38.What is the difference between onload() and document.ready()?

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In a page, we can have only one onload function but we can have more than one document.ready function. Document.ready function is called when DOM is loaded but onload function is called when DOM and images are loaded on the page.

Q39.What is the use of jQuery each function?

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jQuery each function is used to loop through each and every element of the target jQuery object. It is also useful for multi element DOM, looping arrays and object properties.

Q40.How method can be called inside code behind using jQuery?

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$.ajax can be called and by declaring WebMethod inside code behind using jQuery.

Q41.Which is the fastest selector in jQuery?

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ID and Element are the fastest selectors in jQuery.

Q42.What is the slowest selector in jQuery?

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Class selectors are the slowest selectors in jQuery.

Q43.Where jQuery code is getting executed?

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jQuery code is getting executed on a client browser.

Q44.What is the method used to define the specific character in place of $ sign?

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‘NoConflict’ method is used to reference a jQuery and save it in a variable. That variable can be used instead of Sign.

Q45.Why jQuery is better than JavaScript?

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jQuery is a library used for developing Ajax application and it helps to write the code clean and concise. It also handles events, animation and Ajax support applications.

Q46.What are the types of selectors in jQuery?

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There are three types of selectors in jQuery:

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CSS Selector

XPath Selector

Custom Selector

Conclusion:

These jQuery interview questions are carefully selected to aid you in your preparation. We hope they prove beneficial for your upcoming interview. Take the time to thoroughly prepare these questions to increase your confidence and chances of success. If you have any further questions or suggestions, feel free to leave a comment below or reach out to us. Best of luck!