jQuery Interview Questions and Answers

0
100 jQuery Interview Questions and Answers

  1. What is jQuery?

    • Answer: jQuery is a fast, small, and feature-rich JavaScript library. It simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development. It aims to make JavaScript easier to use and write by providing a consistent, cross-browser API.

  2. How do you select elements using jQuery?

    • Answer: jQuery uses the dollar sign ($) as its selector. For example, `$(“#myId”)` selects an element with the ID "myId", `$(“.myClass”)` selects all elements with the class "myClass", and `$("p")` selects all paragraph elements.

  3. Explain the difference between `$()` and `jQuery()`?

    • Answer: `$()` is a shorthand for `jQuery()`. They are functionally identical; both are used to create jQuery objects.

  4. How do you handle events in jQuery?

    • Answer: jQuery provides methods like `.click()`, `.mouseover()`, `.mouseout()`, `.keydown()`, etc., to attach event handlers to elements. For example, `$("#myButton").click(function() { /* code to execute on click */ });` attaches a click handler to the button with the ID "myButton".

  5. What is the purpose of `$(document).ready()`?

    • Answer: `$(document).ready()` ensures that the jQuery code runs only after the entire HTML document has been completely loaded and parsed. This prevents errors that might occur if you try to manipulate elements that haven't yet been loaded.

  6. How do you perform DOM manipulation with jQuery?

    • Answer: jQuery simplifies DOM manipulation. You can use methods like `.append()`, `.prepend()`, `.after()`, `.before()`, `.remove()`, `.empty()`, `.html()`, `.text()` and `.attr()` to add, remove, or modify elements and their content.

  7. Explain jQuery's chaining method.

    • Answer: jQuery's chaining allows you to perform multiple actions on the same set of elements in a single line of code. Each method returns the jQuery object, allowing you to chain methods together. For example: `$("#myDiv").addClass("highlight").css("color", "red").show();`

  8. How do you use jQuery to make an AJAX call?

    • Answer: jQuery's `.ajax()` method simplifies AJAX calls. You specify the URL, method (GET or POST), data, and success/error callbacks. For example: `$.ajax({ url: "/myurl", method: "POST", data: {param1: "value1"}, success: function(response) {/*process response*/} });` $.get() and $.post() are also common shortcuts.

  9. What are jQuery effects? Give examples.

    • Answer: jQuery effects provide methods for creating animations and visual transitions. Examples include `.hide()`, `.show()`, `.fadeIn()`, `.fadeOut()`, `.slideUp()`, `.slideDown()`, `.animate()`, etc.

Thank you for reading our blog post on 'jQuery Interview Questions and Answers'.We hope you found it informative and useful.Stay tuned for more insightful content!