JS学习笔记1-原型

function user(name,age,gender ) {
    var person= {};
    person. name =name;
    person.age = age;
    person.gender = gender;
    return person;
}
var whh= user("王花花",18,"male")
console.log(whh);

工厂函数，用作生成对象

function User(name,age,gender) {
    this.name=name;
    this.age= age;
    this.gender=gender;

}
var whh2= new User("王花花2",28,"female")
console.log(whh2)

• 构造函数
• 没有return关键词 必须用new
• 一般首字母会大写

var a = {};
console.log(a);

点开后_proto_:下constructor:f Object()
即

var a = {}

var a = new Object ()

两者相等

var a = Object.creat(null)

创建不带任何继承对象的方法

var a = Object.creat(
    a=1,
    b=2
)

同样也可以使用这个方法自定义继承

function 原型(属性1,属性2){
    this.属性1=属性1;
    this.属性2=属性2;
}
//上面为原型
function 继承1(){}
继承1.prototype = Object.creat( 原型.prototype);
继承1.prototype.功能1 = console. log("功能1");c
//用Object.creat 方法创建继承链

下面是某个实例

//动物
function Animal(color, weight) {
    this.color = color;
    this.weight = weight
}
Animal.prototype.eat = function () {
    console.log("吃东西");
}
Animal.prototype.sleep = function () {
    console.log("睡觉");
};
//哺乳动物
function Mammal(color, weight) {
    Animal.call(this,color,weight)
}
Mammal.prototype = Object
![](https://user-gold-cdn.xitu.io/2019/9/7/16d08cae841dd134?w=2370&h=824&f=png&s=121503).create(Animal.prototype);
Mammal.prototype.constructor = Mammal
Mammal.prototype.suckle = function () {
    console.log("吃奶");
}

var b = new Mammal();
//人类
function Person(color,weight) {
mammal.call(this,color,weight)
}
Person.prototype = Object.create(Mammal.prototype);
// Person.prototype.constructor = Person
Person.prototype.lie = function(){
    console.log("说谎");
}
var c = new Person()

涉及到了一些关于call this 的知识，以后的博客中会补全