Interview questions on JQuery

We have listed down some of the most frequently asked Interview questions of JQuery. These questions curated by the experts so that you don’t have to go anywhere. Here we will bestow the in-depth knowledge about JQuery so that you can bag down your dream job.

Que 1. Define JQuery?

Answer. JQuery was first released on August 26, 2006, and it is free and open-source software using permissive MIT license. JQuery’s syntax is designed to make it easier to navigate a document, select DOM elements, create animations, handle events, and develop Ajax applications. JQuery also provides developers with the ability to create JavaScript plug-ins.

Que 2. What are the advantages of JQuery?

Answer. It’s like an enhanced JavaScript version, so learning a new syntax has no overhead.
It gives hundreds of plug-ins for everything.
JQuery has cross-border support.
This would eliminate the need to write complex loops and library calls for DOM scripting.
JQuery is capable of keeping the code short, easy to read, straightforward and reusable.

Que 3. Name the methods that provide effects to JQuery?
Answer.

Fade In ()
Fade out ()
Show ()
Hide ()
Toggle ()

Que 4. What is the difference between the ID selector and class Selector in JQuery?
Answer. If you’ve used CSS, you might know the difference between the ID and the class selector, jQuery is the same. ID selector uses ID for selecting elements, e.g. #element1, while class selector uses CSS for selecting items. When selecting just one element, use the ID selector while selecting a group of elements with the same CSS class as using the class selector. The interviewer is likely to ask you to write code using the ID and class selector. From the point of view of syntax, as you can see, another difference is that the former uses “#” and later uses.” “character.

Que 5. What do you mean by booking?
Answer. If more than one selector shares the same statement, they can be grouped together through a comma-separated list; this enables you to reduce the size of the CSS (every bit and byte is important) and make it more readable. The following snippet applies the same background to the h1, h2, h3 {background: blue;}.

Que 6. Name the compatible operating system with JQuery?
Answer
Windows
Mac
Linux
Que 7. How you can read, write and delete cookies in Jquery?
Answer. Using the Dough cookie plugin, we can handle jquery cookies. Dough is user-friendly and features powerful.

Create cookie:
1
$. dough(“cookie_name”, “cookie_value”);
Read Cookie:
1
$. dough(“cookie_name”);
Delete cookie:
1
$. dough(“cookie_name”, “remove”);

Que 8. What do you mean by JQuery connect? And also tell how to use it?
Answer. A jQuery connect is a plugin for connecting or binding a function to another function. Connect is used from any other function or plugin to perform a function. Through downloading the jQuery link file from jQuery official website, it can be used to include that file in the HTML document. To connect one function to another, you need to use $. connect.

Que 9. Is there any program for testing JQuery? If yes, name it?
Answer. Yes, there is a program for testing JQuery. QUnit is used to test jQuery and it is very easy and efficient.

Que 10. What do you mean by Jquery UI?
Answer. JQuery UI is a set of jQuery JavaScript Library user interactions, effects, widgets, and themes. JQuery UI works well for highly interactive web applications with a variety of controls or simple date picker pages.

Que 11. What is the use of the HTML() method in JQuery?
Answer. The method jQuery HTML() is used to change the selected elements ‘ entire content. It replaces the content of the selected component with new content.

$(document).ready(function(){
$(“button”).click(function(){
$(“p”).html(“Hello Codersera”);
});
});

Que 12. What is the use of Jquery.each () function?
Answer. The function “jQuery.each()” is a general function that loops through a set (a type of entity or type of array). The index position and value of array-like objects with a length property are iterated. Certain objects are iterated on the properties of their primary value.

Nevertheless, the function “jQuery.each()” works differently from the function $(selector).each() that uses the selector to operate on the DOM component. But both iterate about an element of jQuery.

Syntax:

< script type = "text/javascript" >
$(document).ready(function() {
var arr = ["Mary", "John", "Garry", "Tina", "Daisy"];
$.each(arr, function(index, value) {
alert('Position is : ' + index + ' And Value is : ' + value);
});
}); < /script>

Que 13. How can you debug JQuery?
Answer. There can be two ways to debug JQuery:-

Add the debugger to the line from which to debug and run Visual Studio with the F5 function key in debug mode.
Insert a breakpoint after attaching the process.

Que 14. Can Jquery be replaceable with JavaScript?
Answer. NO, JQuery is not a replacement for JavaScript.

Que 15. Differentiate between prop and attr?
Answer. JQuery. prop() – It gets a property value in the matched element set for the first element.

JQuery. Attr()– In the matched element set, it gets the value of an attribute for the first element.

Attributes contain additional HTML element information and come in pairs of name=”value”. You can set and specify an attribute for an HTML element when the source code is published.

For Eg -
Here, “id”, “type” and “value” are attributes of the input elements.