JS Bin// source http://jsbin.com/dovatoruzu

the dot notation usage

function createMe(config){
  return {
    callMeString: function(){
      console.log('who: ' + config);
    },
    callMeObject: function(){
      console.log('who: ' + (config && config.who));
    }
  };
}


//this will work
console.info('This will work');
var obj = {};
var meObj = createMe(obj);
obj.who = 'my name';
meObj.callMeObject();

//this will not work
console.warn('This will not work');
var str = '';
var meStr = createMe(str);
str = 'shlomi';
meStr.callMeObject();