es6继承
class father{
constructor(x,y){
this.x=x;
this.y=y;
}
ddd(){}
}
class son extends father{
constructor(x,y,z){
super(x,y);
this.z=z;
}
ggg(){}
}
var r=new son(1,2,3);
console.log(r.__proto__===son.prototype);
console.log(r.__proto__);
console.log(son.prototype);
console.log(father.prototype);
console.log(r instanceof son);
console.log( r instanceof father);
console.log( r.__proto__===son.prototype);//true
console.log(son.__proto__===father);//true
console.log(son.__proto__);//father 类
console.log(son.prototype);//class子类对象
可见 r.__proto__===son;
son.protopype==father;
son.__proto__=class son extends father{....}