Object-oriented - prototype

Object-oriented - prototype

1. Object Oriented (OOP)

1.内置对象
//构造函数function Array(){}  //由于window内置了所以不用写直接实例化就好了
//Array是内置对象
var arr1 = new Array（1,2,3）; 
var arr2 = new Array(4,5,6);

alert（arr1.constructor）; //constructor可以获取实例对象的构造函数
alert（arr1.push == arr2.push） //true  //这里可以说明他们共用一个方法

//构造函数的特点：首字母大写，new关键字就行调用，this指向实例对象
2.构造函数实现面向对象
function Abc(name){
    this.name = name;
    this.showname = function(){
        return this.name
    }
}

var a1 = new Abc('zhangsan');
var a2 = new Abc('wangwu');
alert(a1.showname()) //输出zhangsan
alert（a1.showname == a2.showname） //false 此时不在是同一个方法 为什么呢？

The constructor of the drawbacks: for instance for each method, we must re-create once, properties and methods inside constructors are private.

Summary: The method object instance constructor object systems are built the same method

We own instance of an object's constructor method is not the same method

​

True object-oriented: Hybrid development (+ constructor prototype)

The constructor for: Properties and Methods of the interior is different

Built-in objects: internal property methods are the same

//构造函数
function Abc(name){   //构造函数内部的属性和方法都是不同的，私有的
    this.name = name;
    this.showname = function(){
        return this.name
    }
}

​

prototype

Prototype: Each function has a convention prototype (prototype property of the object), is placed inside the public properties and methods, this prototype is still inside the instance object points

function Abc(name){   
    this.name = name;
    this.showname = function(){
        return this.name
    }
}

Abc.prototype.showname = function(){
    return this.name;
}
var a1 = new Abc('zhangsan');
var a2 = new Abc('wangwu');

//就在这个时候突然发现  //alert（a1.showname == a2.showname） //true

总结：公有的方法都放在原型下面 属性放在构造函数下面