大家看一下这个函数输出什么结果
function Person(name, age) {
this.name = name;
this.age = age;
this.friends = ["hello", "test"];
}
Person.prototype = {
constructor:Person,
sayName: function() {
alert(this.name);
}

}
var person1 = new Person("wang", 32);
alert(person1.sayName());

[解决办法]

JScript code

function Person(name, age) {     this.name = name;  this.age = age;  this.friends = ["hello", "test"];  }  Person.prototype = {     constructor:Person,  sayName: function() {  alert(this.name);  }  }  var person1 = new Person("wang", 32);  alert(person1.sayName());//先弹出'wang'，再弹出undefined，弹出undefined是因为person的sayName方法没有返回值  person1.sayName();
[解决办法]
第一次输出wang // 构造函数
第二次输出undefined //sayName无返回值，所以alert的结果是undefined