jQuery Interview Questions and Answers | Set-3

We have already discussed some jQuery interview questions.

• jQuery Interview Questions and Answers | Set-1
• jQuery Interview Questions and Answers | Set-2

Below are some more related questions:

1. What is method chaining in jQuery ? What advantages does it offer ? Method chaining is a feature of jQuery that allows chain together multiple methods in a single statement on a single element. Advantage: By combining or “chaining” multiple methods, you can seriously cut down on the number of times you make your browser look for the same elements without having to set any variables.
2. What is the difference between jQuery.get() and jQuery.ajax() method ? The ajax() method in jQuery is used to perform an AJAX request or asynchronous HTTP request. The jQuery .get() method loads the data from server by using the GET HTTP request. This method returns XMLHttpRequest object.
3. What is a Data Table plug-in for jQuery ? DataTables is a plug-in for the jQuery, JavaScript library. It is a highly versatile tool, built upon the foundations of progressive improvement, that adds advanced options to any HTML table.
4. Where jQuery code is getting executed ? Client side (Browsers) are used to execute the jQuery codes.
5. Explain and contrast the usage of event.preventDefault() and event.stopPropagation() method. The preventDefault() Method in jQuery is used to stop the default action of selected element to occur. It is used to check whether preventDefault() method is called for the selected element or not. The event.stopPropagation() method is an inbuilt method in jQuery which is used to stop the windows propagation. In the DOM tree, when setting an event with the child element and the parent element as well then if you hit on the child element event it will call both child and the parent element as well.
6. What is the proper way in jQuery to remove an element from the DOM before its Promise is resolved ? A returned Promise in jQuery is connected to a delayed object stored on the data() for an element. Since the remove() method removes the element’s data still because of the element itself. It will prevent any of the element’s unresolved promises from resolving. Therefore, it is necessary to remove an element from the DOM before its Promise is resolved. Use detach() method instead and follow with removeData() method when resolution.
7. What is the slowest selector in jQuery ? Class selectors are the slowest selectors in jQuery.
8. Which is the fastest selector in jQuery ? ID and Element selector are the fastest selectors in jQuery.
9. What is the difference between document.ready() and window.onload() method ? The document.ready() event happens once all HTML documents are loaded, however window.onload() happens once all content (including images) has been loaded. So, the document.ready() event fires first.
10. How method can be called inside code behind using jQuery ? $.ajax can be called and by declaring Web Method inside code behind using jQuery.
11. How to work with parent(), children() and siblings() methods in jQuery ? The parent() method returns the parent of the chosen element by calling the jQuery parent() method. The siblings() method returns all the siblings of given HTML elements.
12. What is the use of jQuery each function ? jQuery each function is used to loop through each and every element of the target jQuery object. It is conjointly helpful for multi-element DOM, looping arrays and object properties.
13. Define slideToggle() effect ? The slide methods do the up and down element. To implement slide up and down on jQuery element, the area unit the three methods:
    • slideDown()
    • slideUp()
    • slideToggle()
14. Where can we download JQuery ? jQuery, JavaScript can be downloaded from jQuery official website – https://jquery.com//
15. Define bind() and unbind() elements in jQuery ? The jQuery bind() method attaches an event handler to elements, whereas unbind() detaches an existing event handler from elements. Use basic HTML code to form the HTML elements.
16. Is jQuery is a replacement of JavaScript ? No, jQuery is not a replacement of JavaScript.
17. How to find browser and browser version in jQuery ? Using $.browser property of jQuery returns the browser info. Using $.browser isn't suggested by jQuery itself, thus this feature has been moved to the jQuery.migrate plugin that is accessible for downloading if the user desires.
    • It is a vulnerable practice to use the same. Use it only if needed.
    • It is continuously higher to not use browser-specific codes.
18. What are all the ways to include jQuery in a page ? Following are the ways to incorporate jQuery during a page:
    • Local copy inside script tag
    • Remote copy of jQuery.com
    • Remote copy of Ajax API
    • Local copy of script manager control
    • Embedded script using client script object
19. How can we debug jQuery ? There are two ways to debug jQuery code: Debugger keyword
    • Add the debugger to the line from wherever we have to start out debugging and run Visual Studio in debug mode with F5 function key.
    • Insert a breakpoint after attaching the process.
20. How to check the data type of any variable in jQuery ? Use $.type(Object) method to get the data-type of object.