javascript document ready for specific page code example

Example 1: dom ready js

document.addEventListener("DOMContentLoaded", function() {
  // code
});

Example 2: jquery document ready

The .ready() method is typically used with an anonymous function:
$( document ).ready(function() {
  // Handler for .ready() called.
});

Which is equivalent to the recommended way of calling:
$(function() {
  // Handler for .ready() called.
});

Example 3: jquery check if document loaded

jQuery offers several ways to attach a function that will run when the DOM is ready. All of the following syntaxes are equivalent:

$( handler )
$( document ).ready( handler )
$( "document" ).ready( handler )
$( "img" ).ready( handler )
$().ready( handler )