Top jQuery Interview Questions You Should Know in 2023<

Preparing for a jQuery interview? While modern JavaScript frameworks like React and Vue are popular, jQuery still plays a key role in many web projects—especially legacy systems. If you’re applying for front-end roles, a strong understanding of jQuery can give you a competitive edge.

In this post, we’ll go over 10 commonly asked jQuery interview questions. Whether you’re brushing up or learning jQuery from scratch, this guide will help you prepare with clarity and confidence.

1. What is jQuery and Why Do Developers Use It?

jQuery is a fast, small, and feature-rich JavaScript library that simplifies HTML DOM manipulation, event handling, animations, and AJAX interactions. It became popular for helping developers write less code while handling browser inconsistencies with ease.

• Improves productivity
• Makes JavaScript easier to write and maintain
• Offers simple syntax for complex tasks

2. How Do You Select Elements in jQuery?

jQuery selectors let you select and manipulate HTML elements with CSS-like syntax:

$('#id')             // By ID
$('.class')         // By class
$('div')            // By tag
$('[type="text"]')  // By attribute

3. What is Event Delegation in jQuery?

Event delegation allows you to attach a single event listener to a parent element that handles events for its children—even if they’re added dynamically.

$('#parent').on('click', '.child', function () {
  alert('Child element clicked!');
});

This improves performance and is useful in dynamic interfaces.

4. How Do Animations Work in jQuery?

jQuery offers simple methods to create animations and effects:

$('#box').fadeIn();
$('#box').fadeOut();
$('#box').slideToggle();
$('#box').animate({ width: '300px' }, 500);

5. How Do You Handle AJAX Requests in jQuery?

jQuery simplifies asynchronous requests using .ajax(), .get(), and .post():

$.ajax({
  url: 'data.json',
  method: 'GET',
  success: function (data) {
    console.log(data);
  },
  error: function (err) {
    console.error(err);
  }
});

6. What is Method Chaining in jQuery?

Method chaining allows you to call multiple jQuery methods on the same element in a single line of code:

$('#box')
  .css('background', 'blue')
  .slideUp(500)
  .slideDown(500);

7. What’s the Difference Between .append() and .appendTo()?

Both are used to add elements to the DOM, but the direction of use differs:

$('#container').append('<p>Text</p>');      // Parent.append(child)
$('<p>Text</p>').appendTo('#container'); // Child.appendTo(parent)

8. What is the .each() Function?

.each() is used to loop through jQuery objects or arrays:

$('li').each(function (index, element) {
  console.log(index + ': ' + $(element).text());
});

9. How Can You Prevent Default Behavior in jQuery?

Use event.preventDefault() inside an event handler to stop default actions:

$('a').click(function (e) {
  e.preventDefault();
});

This is useful when you want to override browser defaults, like form submissions or link redirects.

10. Solve a Real-World Problem Using jQuery

Example: Highlight all empty input fields when submitting a form:

$('form').submit(function (e) {
  e.preventDefault();
  $('input').each(function () {
    if (!$(this).val()) {
      $(this).css('border', '1px solid red');
    }
  });
});

This kind of practical demonstration shows that you can apply jQuery to real-world situations.

Conclusion

Even though newer frameworks have taken center stage, jQuery is still used in many web applications today. Understanding how and when to use it can give you an advantage—especially in roles that maintain or integrate with older codebases.

Use these questions as a foundation for your prep. Practice writing code, review the jQuery documentation, and most importantly—understand the “why” behind each answer.

Good luck with your interview prep!