JQuery interview questions and Answers

Last updated on Jan 09, 2023
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JQuery interview questions

jQuery is a feature-rich, lightweight, and fast JavaScript library, which makes HTML documents, event handling, Ajax, and animation easier with a simple API that works across almost all browsers. These jQuery interview questions will enhance your skills and help you to write in a mainstream JavaScript library, used by major players. The critical purpose of jQuery is to make using JavaScript more convenient on your website. A great combination of extensibility and flexibility, jQuery takes a lot of general tasks that require multiple lines of JavaScript code and wraps them in a manner that you can use with a single line of code.

Most Frequently Asked JQuery interview questions

Here in this article, we will be listing frequently asked JQuery interview questions and Answers with the belief that they will be helpful for you to gain higher marks. Also, to let you know that this article has been written under the guidance of industry professionals and covered all the current competencies.

Q1. What is serialize() in Jquery?
Answer

In the standard URL- encoded notation jQuery serialize() is used to create the text strings. It also forms several other controls.
 

$("button").click(function(){
    $("div").text($("form").serialize());
});

Q2. What are the difference between alert() and confirm()?
Answer

Alert()- it is a pop up that is intended for the user to click the OK button and vanish once you click.

Confirm ()- it is a wider choice and gives 2 options to the user to choose. It is basically like an if-else statement.

Example

Display message with alert() and confirm()

alert('Are you sure to delete this item?');
confirm("Are you sure to delete this item?");

Q3. What is the difference between onclick and onsubmit?
Answer

Onclick- it is a mouse event and occurs when the user clicks the left button of the mouse.

Onsubmit- it is a form event and occurs when a user is trying to submit the form. When form validation is used, then this is considered.

Example

$("p").click(function(){
     alert("You clicked here");
});

$("form").submit(function(){
    alert("You form submitted");
});

Q4. How to concatenate two strings using jQuery?
Answer

In order to concatenate two strings in jQuery concatenate the strings using + consternation operator. You have to follow a sequence of codes soon after it. Once it is done, the strings get concatenate. There are some other alternatives as well.

Example

var a = 'Best Interview';
var b = 'Question';
var result = a + b;

// output
Best Interview Question

Q5. How we can check if an element is empty or not using Jquery?
Answer

You can check it in various ways.

if ($('#element').is(':empty')){
   //write your code here
}

OR

if ( $('#element').text().length == 0 ) {
   // length is 0
}

Q6. What are the difference between empty(), remove() and detach() functions in jQuery?
Answer
remove() detach() empty()
through it matched elements can be removed completely from the DOM it is more like with remove function, but it stores the data associated with elements. it removes all the child elements from the data.
Q7. Explain various methods to make ajax request in jQuery?
Answer
  • $.ajax() - for async request
  • $.ajaxsetup()- to set default value
  • $.ajaxTransport()- for object transmission
  • $.get() - loads data
  • $.ajaxPrefilter()- handle custom solutions
  • $.getJSON() - loads JSON data
Q8. What is the latest version of jQuery?
Answer

The latest version of jQuery is jQuery3.3

Q9. What is the difference between text() and HTML() in jQuery?
Answer

The text() method return text value inside an HTML element whereas HTML() method returns the entire HTML syntax.

The text() method is used to manipulate the value and the HTML() method is used to manage the HTML object or properties.

Q10. How to use css() in JQuery?
Answer

With the help of CSS() method, we can add or remove CSS properties to an HTML element.

Example

Syntax
$(selector).css(property);

$("#divID").css("display", "block");

Development History of jQuery

jQuery was released by John Resig at the BarCamp NYC in January 2006. Currently, it is headed by Timmy Wilson and managed by a team of expert developers.

Latest Version: The most recent version is 3.5.0, which was released on 4th May 2020.

Advantages
  • Easy to learn and intuitive
  • Deals with many cross-browser bugs
  • Clean and simple syntax
  • Open source library
  • Highly extensible

These jQuery interview questions will help you prepare for your upcoming job interview as well and fast-track your career, whether you are a fresher or an experienced Jquery developer.

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