Job Interview Questions Of jQuery

IS JQUERY CONSIDERED TO BE A PROGRAMMING LANGUAGE ?

No, we can't considered jQuery as a programming language, but we can say it is a well-written JavaScript code which we use to traverse documents, event handling, AJAX interactions and etc.

METHODS WHICH USE TO PROVIDE THE EFFECTS ?

Some of the effect methods of jQuery are as follows:-

• show()
• hide()
• fadeIn()
• fadeOut()
• toggle()

CAN WE ABLE TO USE JQUERY IN XHTML DOCUMENTS ?

The answer is simply, no. We can only able to use the jQuery with HTML documents.

ADVANTAGES OF JQUERY ?

• Easy to use and learn
• Can use to develop browser compatible web applications
• Very fast and extensible
• It faciliate us to write minimal lines of code for UI related functions
• It provide the cross-browser support

DISADVANTAGES OF JQUERY ?

• There are limited functionality
• jQuery JavaScript file is required to use jQuery in the document.

WHAT IS $() IN JQUERY ?

The $() function is an alias of jQuery function. It is used to define or access jQuery.

FEATURES OF JQUERY ?

Some of the key features of jQuery are as follows:-

• Event we can able to handle easily
• DOM Manipulation means easily we can select the DOM elements, traverse them and easily modify the content
• Using AJAX texhnology we can develop responsive and feature-rich website
• Good cross browser support
• It is very lightweight library- just 19kb in size
• Can build multi animation effects which we can use in our website

DIFFERENT TYPES OF SELECTORS IN JQUERY ?

There are mainly 3 types of selectors which are as follows:-

• By Tag Name
• By ID
• By Class

CHAINING IN JQUERY ?

Chaining in jQuery lets you run multiple statements one after another on the same element. We need to append each jQuery command to the previous one using dot(.).
For example:- $("#p").css("color", "red").slideUp(400).slideDown(200);

DIFFERENCE BETWEEN PROPS AND ATTR OF JQUERY ?

Although both are used to get or set the value of the specified property of an element attribute where:-

jQuery.prop():- Use to return the current value.

jQuery.attr():- Use to return the default value of property.

FULL FORM OF CDN. AND ENLIST THE TYPES OF JQUERY CDN ?

CDN stands for Content Distribution Network. And there are 2 types of CDNs:-

• Microsoft:- Load jQuery from AJAX CDN.
• Google:- Load jQuery from Google libraries API

WHY JQUERY IS BETTER THAN JAVASCRIPT ?

Fisrt of all jQuery is a concise which means we don't need to write much script or code. Also it simplifies HTML document traversing, event handling, animating, and AJAX interaction for faster web development.

WHAT IS THE USE OF TOGGLE() METHOD IN JQUERY ?

It is used to toggle between the hide() and show() method. In simple words, it shows the hidden elements and hides the shown element.

WHAT IS THE USE OF FADETOGGLE() METHOD IN JQUERY ?

It is used to toggle between the fadeIn() and fadeOut() method. In simple words, it fades out to the fade in element and fades in to the fade out element.

WHAT IS THE JQUERY MOBILE ?

It is an HTML-based user interface system designed to make responsive websites and apps accessible on every smartphones, tablets and desktop devices.

WHAT IS THE USE OF DELAY() METHOD IN JQUERY ?

The delay() method is use to delay the execution of functions in the queue. It can sets a timer to delay the execution of the next item in a queue.

WHAT IS JQUERY UI ?

jQuery UI is a set of user interface interactions, effects, widgets, and themes built on top of the jQuery JavaScript library. It very well works for highly interactive web applications with many controls for a simple type page with a date picker control.

WHAT IS THE USE OF JQUERY FILTER ?

To filter the specific values from the object we use jQuery filter. It filters the original query into specified element.

WHAT IS THE USE OF SLIDETOGGLE () EFFECT ?

slideToggle() method is used to toggle between sliding up and sliding down for the selected elements.

WHERE JQUERY CAN REALLY BE USED ?

• For animation purpose
• Apply static or dynamic CSS
• Manipulation Process
• Calling functions on events

WHICH IS THE FASTEST SELECTOR IN JQUERY ?

ID and Element are the fastest selector in jQuery.

WHICH IS THE SLOWEST SELECTOR IN JQUERY ?

Class selector are the slowest selector in jQuery.

WHAT IS THE USE OF VAL() METHOD IN JQUERY ?

If we want to get the current value of the first element in the set of the matched element, than this method we can use. Also we can able to set the value of every matched element through this same method.

LIST DIFFERENT CATEGORIES OF JQUERY EVENTS ?

• Keyboard events such as keyup and keydown
• Mouse events such as click and dblclick
• Form events such as submit, focus and change
• Document / Window events such as load, unload and scroll

WHAT IS THE SLICE() METHOD IN JQUERY ?

This slice() method selects a subset of the matched elements based on its index. And subset is basically a set which is a part of larger set.

WHAT IS THE USE OF JQUERY EACH FUNCTION ?

jQuery each function is used to loop through each and every element of the particular targeted jQuery object. Can also useful for multi-element DOM, looping arrays and object properties.

HOW WE CAN READ, WRITE AND DELETE COOKIES IN JQUERY ?

To deal with the cookies here in jQuery, we need to use the Dough cookies plugin.

WHAT IS THE USE OF SERIALIZE() METHOD IN JQUERY ?

The serialize() method is used to create a text string in the standard URL-encoded notation. It can serializes the form values so that its serialized values can be used in the URL query string while making an AJAX request.

WHAT IS THE USE OF CSS() METHOD IN JQUERY ?

The css() method is used to set the style properties or values for the selected elements. We can also add multiple properties or values.

HOW JQUERY STORES DATA RELATED TO AN ELEMENT ?

Through jQuery.data() method, we can add or attach any data type to DOM elements, free from memory leaks. jQuery also make sure that data is been removed too when the DOM elements removed through jQuery methods.

WHAT IS JQUERY CLICK EVENT ?

jQuery click() method triggers the click event, or attaches a function to run when the click event occurs.

WHAT IS QUNIT ?

qUnit is a framework, which tests JavaScript code written for jQuery, jQuery UI and jQuery Mobile and test fixtures for verifying the expected results.

WHAT IS THE FINISH() METHOD IN JQUERY ?

To stop all the queued animations and to help them place in their final state the .finish() method is used.

FUNCTIONING OF CONNECT() METHOD IN JQUERY ?

jQuery connect() is a plugin that can be used to connect/bind a function to the another function by assigning a handler. We can use an event of a DOM element using this connect() method.

SIGNIFICANCE OF JQUERY.LENGTH ?

This jQuery.length property is used to count the total number of elements of the jQuery object.

WHAT IS THE PROMISE() METHOD USED FOR IN JQUERY ?

The promise() method is used to return a dynamically generated promise that is resolved when all actions like collection of certain type bound are quesues or have not ended.

WHAT IS JQUERY.NOCOFLICT METHOD ?

To overcome the conflicts between different libraries and frameworks jQuery has given the option of jQuery no-conflict option. Baically it helps us to overcome all the conflicts.

WHAT IS PREVENT DEFAULT OF ANY EVENT ?

To stope the default action of an element, we can use this preventDefault() method. Baically it halt the default action from happening.

LATEST VERSION OF JQUERY LIBRARY ?

The latest version of jQuery library is jQuery 3.6.0.

HOW WE CAN CHECK THE DATA TYPE OF ANY VARIABLE USING JQUERY ?

To achieve any data type of any variable using jQuery, we can simply use $.type(Object) which returns the built-in JavaScript type for an object.

HOW CAN WE ABLE TO SELECT ALL THE ELEMENTS USING JQUERY ?

To select all the elements in jQuery, we can simply use the $("*").

HOW WE CAN ABLE TO SEARCH FOR THE DESCENDANT ELEMENTS THAT MATCH THE SPECIFIED SELECTOR USING JQUERY ?

We can use find(selector) method to search for the descendant elements that matched the specified selector using jQuery.

LIST DIFFERENT JQUERY AJAX EVENTS ?

• ajaxStart()
• ajaxSend()
• ajaxError()
• ajaxComplete()
• ajaxSuccess()
• ajaxStop()

WHAT IS PARENT() IN JQUERY ?

This parent() method refers to the top-level elements in the particular HTML objects, that are been selected by jQuery selector. It is mainly used to manipulate changes to the top-level of a nested HTML object.

WHAT IS .END() METHOD IN JQUERY ?

jQuery end() method is use to end the most recent filtering operation in the current chain and use to return the perfect matched set of factors.

HOW CAN WE ADD OR REMOVE CLASSES TO AN ELEMENT IN JQUERY ?

jQuery has its own two syntaxes, addClass() and removeClass() where through addClass() method we can attach the class and through removeClass() we can detach or remove the class.