var object = {

             name : 'The Kite Runner',

             obj : {

                 name : 'childProperty',

                 fn : function(x, y){

                     var result = x + y;

                     console.log('this-context'+this);

                     console.log('this-property'+this.name);

                     console.log('result'+result);

                 }

             }

         }

         var f = object.obj.fn;  //函数引用

         f();  // this --window

         //修改this指向--object.obj对象

         f.apply(object.obj, [10,25]);

         f.call(object.obj, 25,45);