jQuery Interview Questions

What is $() in jQuery library?

$() in jQuery is a function used for selecting and manipulating elements in the Document Object Model (DOM) using CSS-style selectors. It's a core part of jQuery that facilitates DOM manipulation.

What are the advantages of jQuery?

jQuery offers advantages like simplified DOM manipulation, cross-browser compatibility, concise code, built-in animations, and AJAX support. It streamlines JavaScript development and enhances web application interactivity.

What is the basic requirement to start with jQuery?

To start with jQuery, you need to include the jQuery library in your HTML document and have a foundational understanding of HTML and JavaScript.

What is jQuery Mobile?

jQuery Mobile is a framework built on jQuery for creating mobile web applications with consistent user interfaces and touch-optimized interactions across different mobile devices.

Can you use JavaScript and jQuery on the same page?

Yes, you can use JavaScript and jQuery together on the same web page as jQuery is essentially a JavaScript library designed to enhance JavaScript functionality.

What is the difference between jQuery click() and on("click")?

click() attaches an event handler to elements that exist when the code runs, whereas on("click") can attach event handlers to current and future elements, making it suitable for dynamic content.

How to escape HTML strings with jQuery?

You can use the .text() method to escape HTML strings in jQuery, ensuring that HTML tags within the string are treated as plain text and not interpreted as HTML.

What do you mean by Grouping Selectors?

Grouping selectors in jQuery allows you to select multiple elements with a single jQuery statement by separating the selectors with commas. For example, $("div, p") selects all div and p elements.

How to get the current URL with jQuery?

You can get the current URL in jQuery using window.location.href to access the URL of the current page.

What is the best way to detect a mobile device?

The best way to detect a mobile device is by using feature detection techniques or using JavaScript libraries like Modernizr or checking the user-agent string, although this method is less reliable.

What is "Blocked a frame with origin from accessing a cross-origin frame"?

This message indicates a security feature known as the Same-Origin Policy, which restricts web pages from making requests to domains different from the one that served the web page. This message occurs when attempting to access content from a cross-origin frame.

What is noConflict() in jQuery?

noConflict() is a method in jQuery that releases control of the global $ variable, allowing you to use other JavaScript libraries that may also use $ without conflicts.

What is "Origin null is not allowed by Access-Control-Allow-Origin"?

This error occurs when a web page loaded from the local file system (origin null) attempts to make an AJAX request to a different domain. It's a security restriction enforced by the Same-Origin Policy.

Uncaught ReferenceError: $ is not defined?

This error occurs when jQuery is not properly included in your HTML document. Make sure to include the jQuery library using a <script> tag before your jQuery code.

What is the difference between eq() and get() methods in jQuery?

eq() is a jQuery method used to select a specific element from a set of matched elements by index, while get() is a method that retrieves a DOM element from a jQuery object based on its index.

Can we use jQuery to make an AJAX request?

Yes, jQuery provides the .ajax() method for making AJAX requests, simplifying the process of sending and receiving data from a server asynchronously.

What are the four parameters used for the jQuery Ajax method?

The four common parameters used in the jQuery .ajax() method are url (the server URL to send the request to), data (the data to send to the server), success (a callback function to handle a successful response), and error (a callback function to handle errors).

Advantages Of jQuery in Asp.net web application?

jQuery is beneficial in ASP.NET web applications due to its simplified DOM manipulation, AJAX support for enhanced interactivity, and cross-browser compatibility. It makes client-side scripting more efficient and enhances user experiences.

Last Updated : 02 Sep 2023