function Person(name , age , gender){
this.name = name;
this.age = age;
this.gender = gender;
}
//创建一个Person实例
var per = new Person("孙悟空",18,"男");
console.log(per);
console.log(per.toString());
这个例子视频里是和
返回值都是：
但是我的返回值不一样，如下
image.png
function Person(name , age , gender){
this.name = name;
this.age = age;
this.gender = gender;
}
//创建一个Person实例
var per = new Person("孙悟空",18,"男");
var result = per.toString();
console.log(per.__proto__.__proto__.hasOwnProperty("toString"));
image.png
之所以返回值是 是因为上面这个原因，原型的问题
源码：
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script type="text/javascript">
function Person(name , age , gender){
this.name = name;
this.age = age;
this.gender = gender;
}
//修改Person原型的toString
Person.prototype.toString = function(){
return "Person[name="+this.name+",age="+this.age+",gender="+this.gender+"]";
};
//创建一个Person实例
var per = new Person("孙悟空",18,"男");
var per2 = new Person("猪八戒",28,"男");
//当我们直接在页面中打印一个对象时，事件上是输出的对象的toString()方法的返回值
//如果我们希望在输出对象时不输出[object Object]，可以为对象添加一个toString()方法
//Person[name=孙悟空,age=18,gender=男]
/*per.toString = function(){
return "Person[name="+this.name+",age="+this.age+",gender="+this.gender+"]";
};*/
var result = per.toString();
//console.log("result = " + result);
//console.log(per.__proto__.__proto__.hasOwnProperty("toString"));
console.log(per2);
console.log(per);
</script>
</head>
<body>
</body>
</html>
网友评论