IIFE Javascript Immediately-Invoked Function Expression and passing jQuery

IIFE-examples.js

/**
  * Basic IIFE construction is like this.
  */
(function () { console.log('hello world')})();

/**
  * Basic IIFE which passes in the jQuery object as the $ symbol.
  */
(function ($) { $('div.classname')})(jQuery);

/** 
  * Basic IIFE combined with document ready jQuery idiom. 
  * Assumes you have already loaded jQuery
  */ 
(function ($) { 
  /** 
    * set some variables. 
    * These will only be available to functions within the scope of the IIFE.
    * No danger of redefining variables with names that might be used elsewhere
    * You might use this to set max execution times, or maximum loop counts etc.
    */
  var someVariable = 'Hello World!';

  /**
    * Setup some functions to do stuff
    * Again, these are only available within the IIFE scope. 
    * No danger of redefining similar named functions that might be used elsewhere
    */
  var callAFunction = function(){
    // do something...
    console.log(someVariable);
  };
  
  $(document).ready(function(){
    // do some stuff here when the page has loaded.
    callAFunction();
  });
})(jQuery);