'this' in function inside prototype function [duplicate]

Answer 1

The common work around for that is to use closure

sampleObject.prototype.getFoo = function() {
  var _this = this; 
  var nested = function() {
    return _this.foo;
   }
   return nested();
}

Some libraries add methods to automate this

• Prototype adds Function.bind (http://prototypejs.org/doc/latest/language/Function/prototype/bind/)
• Ext adds function.createDelegate (http://www.sencha.com/learn/Manual:Utilities:Function#createDelegate)
• Javascript 1.8.5 adds function.bind (https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Function/bind)