function Box(){ this.aaa=123; } var box=new Box(); console.log(box.aaa); console.log(box.__proto__); console.log(Box.prototype==box.__proto__); console.log(box.__proto__.constructor.__proto__.constructor); console.log(box.__proto__.constructor);
结果：
原文：http://www.cnblogs.com/change-oneself/p/5036018.html