<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<script type="text/javascript">
function A(name){
this.name=name;
}
function B(age){
this.age=age;
}
function C(sex,name,age){
this.sex=sex;
A.call(this,name);//apply(this,[name])
B.call(this,age)
}
var c=new C('male','wnag',17);
</script>
</body>
</html>
//call需要把实参按照形参的个数传递进去
//apply需要传一个arguments的
//改变this指向 ,传参不同
原型
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<script type="text/javascript">
//Person.prototype---原型
//Person.prototype={}---祖先
Person.prototype.name="like"; //公有祖先
Person.prototype.say=function (){
console.log('love');
}
function Person(age,sex){
this.age=age;
this.sex=sex;
}
var person= new Person(18,'male');
var person1=new Person(40,'femal');
</script>
</body>
</html>
//1.函数对象有_proto_和prototype属性
2.非函数对象只有_proto_属性
3.prototype中有_proto_属性,是Object构造出来的
4.函数对象_proto_指向它的创建者及Function构造函数
5.Function构造函数_proto_指向它自己
6.Object对象的prototype中的_proto_是null
原型链
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<script type="text/javascript">
Grand.prototype.name='wang';
function Grand(){
}
var grand=new Grand();
Father.prototype=grand;
function Father(){
this.name='xu';
}
var father=new Father();
Person.prototype=father;
function Person(){
this.hobbit='woshiwudi';
}
var person =new Person();
</script>
</body>
</html>
var son={
name:'lang';
}
var person=Object.create(son);
Object.create(null)没有原型