Top 10 JQuery Interview Questions and Answers.
1. What is JQuery?
JQuery is a fast, small, and feature-rich JavaScript library. It simplifies things like HTML document traversal and manipulation, event handling, and animation with an easy-to-use API that works across many browsers. With versatility and extensibility, jQuery has changed how millions of people write JavaScript.
2. How JavaScript and jQuery are different?
JavaScript is a language While jQuery is a library built in the JavaScript language that helps to use the JavaScript language.
3. What is the difference between .js and .min.js?
jQuery library comes in 2 different versions Development and Production/Deployment. The deployment version is also known as minified version. So .min.js is basically the minified version of jQuery library file. Both the files are same as far as functionality is concerned. but .min.js is quite small in size so it loads quickly and saves bandwidth.
4. What is the use of jquery .each() function?
The $.each() function is used to iterate over a jQuery object. The $.each() function can be used to iterate over any collection, whether it is an object or an array.
5. What are different selectors in jQuery used for?
jQuery Selectors are used to select and manipulate HTML elements in a webpage. It always start with dollar sign and parentheses. They are very important part of jQuery library. There are three types of selectors in jQuery
- CSS Selector
- Custom Selector
- XPath Selector
Note:
- $('div') is used for selection all div tags in the document,
- $('#TextId') is used for selecting elements whose ID is TextId
- $('.myclass') is used for selecting all elements whose class is .myclass.
6. Differentiate among .empty() vs .remove() vs .detach() in jQuery.
- empty() – This method is used to remove all the child elements from matched elements.
- Syntax- $(selector).empty();
- remove() – This method is used to remove all the matched element. It will remove all the jQuery data associated with the matched element.
- Syntax- $(selector).remove();
- detach() – This method is same as .remove() method except that the .detach() method doesn’t remove jQuery data associated with the matched elements.
- Syntax- $(selector).detach();
7. Explain $(document).ready() function?
This function is used to ensure that the DOM is fully loaded before any jQuery code is executed. This function takes a function as an argument, and the function passed to it will be executed when the DOM is ready. This is useful for ensuring that elements on the page are available before interacting with them.
8. What is the exact difference between the methods onload() and document? ready()?
The onload() method is JavaScript when the page finishes loading. The document. a Ready () method is a jQuery method called when the DOM is ready. The main difference is that onload() waits for all assets on the page to be loaded, including images and other external resources, during the document. Ready () only remains for the DOM to be prepared.
9. tate some different types of jQuery methods.
Some different types of jQuery methods include:
- Event methods: such as click(), hover(), and focus()
- Traversing methods: such as children(), parent(), and siblings()
- DOM manipulation methods: such as append(), prepend(), and replaceWith()
- CSS manipulation methods: such as addClass(), removeClass(), and CSS()
- Animation methods: such as animate(), fadeIn(), and slideUp().
10. Which parameters are being used for the jQuery Ajax method?
JQuery Ajax method makes use of four different parameters which include
* URL – The URL must be clearly specified in order to send the request.
* type – Specifies the type of request(Get or Post)
* data – Specifies data to be sent to the server
* Cache – This tells if the browser should index the specific page or not.
* success(result,status,xhr) – A function to be run when the request succeeds
