Private pattern

Usage of prototype in method 3 of http://eclipsesource.com/blogs/2013/07/05/private-members-in-javascript/

by Kyrylo Slatin

JavaScript

(function (){
    var _;
  MyClass = function( a, b ) { 
      _ = {a: a, b: b};    
  };
  MyClass.prototype.sum = function() {
    return internalCalcSum();
  };
  var internalCalcSum = function() {
    return _.a + _.b;
  };
}());
var m = new MyClass(3, 12);
var sum = m.sum();
console.log(sum);