jquery DOM is ready 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.
});