原型继承
2019-10-20 本文已影响0人
杰克_王_
<!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>原型继承</title>
</head>
<body>
<script>
function Animal(category) {
this.category = category || "Animal";
this.arry = ['a', 'b', 'c'];
}
function Dog(name) {
this.name = name;
this.type = 'dog';
}
// 缺点
// 1. 想为子类添加新的属性或方法，必须放在 new Animal之后
// 2. 无法实现多继承
// 3. 原型链被破坏
// 4. 无法向父级传参
// 5. 引用类型的属性会被影响，比如数组对象会修改到原型上
Dog.prototype = new Animal();
// Dog.prototype.speak = function () {
// console.log('speak');
// }
var dog = new Dog('小白');
// dog.speak();
dog.arry.push('d');
console.log(dog);
</script>
</body>
</html>
