原型链图解

原型链图.png
```<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function Star(uname,age){
            this.uname=uname;
            this.age=age;
        }
        Star.prototype.sing=function(){
            console.log("我会唱歌");
        }
        var ldh=new Star("刘德华",18);
       //1.只要是对象就会有--proto--，指向原型对象
       console.log(Star.prototype);
       console.log(Star.prototype.__proto__===Object.prototype);
       //2.我们Star原型对象里面的__proto__原型指向的Object.prototype
       console.log(Object.prototype.__proto__);  
       //3.我们Object.prototype原型对象里面的————proto————原型指向为null
    </script>
    
</body>
</html>