$(document).ready vs $(window).load vs window.onload
Many time we use ` $(document).ready `when we work with jQuery.This code is written when we execute our code when DOM is ready** except images**.like If our web page has images then it will not wait for loading of images and call and in one page we can apply many document.ready and it call one by one as coming sequence.we call document.ready in many ways like below and they have same functionality and it is jQuery specific event.
//call type 1
$(document).ready(function() {
/** work when all HTML loaded except images and DOM is ready **/
// your code
});
//call type 2
$(function() {
/** work when all HTML loaded except images and DOM is ready **/
//your code
});
//call type 3
$(document).on('ready', function(){
/** work when all HTML loaded except images and DOM is ready **/
//your code
});
//call type 4
jQuery(document).ready(function(){
/** work when all HTML loaded except images and DOM is ready **/
//your code
});
And if we talk about $(window).load then it is work when all DOM is ready including images so it is useful when on document load we want to work with images (calculation of image dimensions) and it is also jQuery specific event.If our web page has images then it will wait for loading of images and then it call.
$(window).load(function() {
/** this is come when complete page is fully loaded, including all frames, objects and images **/
});
and one more thing don’t confuse with window load event with jQuery ajax load method
// load method in jQuery ajax
$("#elementid").load( "data.html" );
The onload event is a standard event in the DOM, while above two are specific to jQuery . this is also same functionality like $(window).load but window.onload is the built-in JavaScript event.The onload event occurs when an object has been loaded.like if we take a example of image and call onload event in image tag then it will call when image will load .generally we use it in body tag.
it is call in HTML and JavaScript like
In HTML
<element onload="myFunction"></element>
In JS
object.onload=function(){/**your desire code**/};// here object can be window,body and etc
1) Here alert “call on body load” call immediately after body has been loaded
In HTML
<!-- on body onload call myFunction -->
<body onload="myFunction()">
In JavaScript
// myFunction() which will call on body load
function myFunction(){
alert("call on body load");
}
if we take a example related to image onload then it will look like below
2) Here alert “call on image load” call immediately after image has been loaded
In HTML
<!-- on image onload call myImageFunction() -->
<img src="image path src" onload="myImageFunction()">
In JavaScript
// myFunction() which will call on image load
function myImageFunction(){
alert("call on image load");
}