best way to call javascript while document loading jquery code example

Example 1: document ready

$( document ).ready(function() {
    console.log( "ready!" );
});

Example 2: jquery doc ready

// A jQuery( document ).ready() block.
jQuery( document ).ready(function() {
    console.log( "ready!" );
});

Example 3: document jquery

$(function(){
  // equal to $( document ).ready(function() {
});