<sctript>

//1.创建父类

function Parent(){

this.name = name;

}

Parent.prototype.age = 20;

//2.创建子类

function Child(){

Parent.call(this,"zhangsan");

}

//3.确立继承关系

Child.prototype = Object.create(Parent.prototype);

//4.改变构造器

Chils.prototype.constuctor = Child;

</script>