<html> <head> <title> wodeweb </title> </head> <body> <script type="text/javascript"> //Object.prototype.color=null; 可去可不去 Object.prototype.shift=function() { //this.color=null;必须去掉否则错误 alert(this.color+(this===Object));//this不是Object } var redCar=new Object(); redCar.color="红色"; var blueCar=new Object(); blueCar.color="蓝色"; redCar.shift(); blueCar.shift(); /*function Car() { this.color=null; //可去可不去 this.shift=function() { alert(this.color+"汽车"); } } var redCar=new Car(); redCar.color="红色"; redCar.shift();*/ </script> </body> </html>