Classic Singleton Patterns

var mySingleton = (function() { 
  //Singleton constructor is private
  function Singleton() {
      var privateVar1 = "I'm a private var";
      this.publicVar1 = "I'm a public var";
      this.publicMethod1 = function() {
          console.log("Private var: " + privateVar1 + " public var: " + this.publicVar1);
      }
  }

  //private var to store the single instance
  var singleInstance;

  //Return the object providing getInstance method
  return {
      getInstance: function() {
          if (!singleInstance) singleInstance = new Singleton();
          return singleInstance;

      }
  }
})();

var myInstance = mySingleton.getInstance();