jQuery Interview Questions (Part-3)

How to debug jQuery?

You can debug jQuery code using browser developer tools like Chrome DevTools or Firefox DevTools. Place breakpoints, inspect variables, and step through your code to identify and fix issues.

Which program is useful for testing jQuery?

Tools like Jasmine, QUnit, and Mocha are useful for testing jQuery code. They provide a framework for writing and running unit tests to ensure the functionality of your code.

Whether jQuery HTML works for both HTML and XML documents?

jQuery's HTML manipulation functions generally work for both HTML and XML documents, as long as the document structure and elements are well-formed XML.

Differentiate the concepts of .js and .min.js?

.js files contain human-readable JavaScript code, while .min.js files are minified versions with whitespace and comments removed, making them smaller in size and faster to load.

Can I use JavaScript and jQuery on the same page?

Yes, you can use JavaScript and jQuery together on the same page, as jQuery is built on JavaScript and complements it for DOM manipulation and other tasks.

Can jQuery work with other JavaScript libraries?

Yes, jQuery can coexist with other JavaScript libraries. You can use jQuery's noConflict() method to avoid conflicts with other libraries that also use the $ symbol.

How to resolve a conflict with another JS library if $ is already in use?

You can resolve conflicts by using jQuery.noConflict() to release the $ symbol, and then use an alternative variable like jQuery to access jQuery functionality.

What are the frequently used types of selectors in jQuery?

Frequently used selectors include element selectors (e.g., $("p")), class selectors (e.g., $(".myClass")), ID selectors (e.g., $("#myId")), and attribute selectors (e.g., $("[data-attr='value']")).

Difference between width() and css('width')?

width() retrieves the computed width of an element, including padding but excluding borders and margins. css('width') retrieves the explicitly set CSS width property, which may not reflect the computed width.

What is the difference between jquery.size() and jquery.length?

jquery.size() is an older method used to determine the number of elements in a jQuery object. jquery.length is a property that provides the same information more efficiently, so it's recommended to use length.

What is the difference between $(this) and this in jQuery?

$(this) wraps the current DOM element in a jQuery object, allowing you to use jQuery methods on it. this refers directly to the DOM element without jQuery methods.

What is the difference between find and children methods?

find searches for descendants of the selected element at all levels, while children only looks for immediate child elements of the selected element.

How to get the direct parent of an element using jQuery?

You can use the .parent() method to get the direct parent element of an element selected with jQuery.

How to get attributes of an element using jQuery?

You can use the .attr('attributeName') method to retrieve the value of an attribute for a selected element.

jQuery interview questions and answers

How do you add an HTML element in the DOM tree?

You can add HTML elements to the DOM tree using jQuery's manipulation methods like .append(), .prepend(), .before(), and .after().

Define bind() and unbind elements in jQuery?

.bind() attaches event handlers to selected elements. .unbind() removes previously attached event handlers, allowing you to unbind specific events from elements.

Differentiate between calling stop(true, true) and finish method?

stop(true, true) stops an animation and jumps to the end, triggering the animation's complete callback. finish also completes the animation but doesn't trigger the callback.

Will Events Are Also Copied On Clone In jQuery?

By default, when you clone an element in jQuery using .clone(), the events associated with the original element are not copied to the cloned element. You need to reattach event handlers to the cloned element if needed.