JS對象添加屬性和方法的多種方式

更新時間：2023年08月18日 09:46:40 作者：西晉的no1

本文介紹了如何使用JavaScript對象添加屬性和方法,通過實例演示了如何給對象添加屬性,以及如何在對象中定義方法,具有一定的參考價值,感興趣的可以了解一下

方式一：定義對象時，直接添加屬性和方法
方式二：通過"對象.屬性名"添加屬性和方法
方式三：通過"對象['屬性名']"添加屬性和方法
方式四：通過 prototype (原型)添加屬性和方法
方式五：使用Object.assign添加屬性和方法
方式六：使用擴展運算符...添加屬性和方法

方式一：定義對象時，直接添加屬性和方法

function Person(name,age,sex){
    this.name = name;
    this.age = age;
    this.sex = sex;
    this.code = function(){
        console.log(this.name + " is coding");
    }
}
var xiaoming = new Person("xiaoming",10,"man");
console.log(xiaoming);// {name: "xiaoming", age: 10, sex: "man", code: ?}
xiaoming.code();// xiaoming is coding

運行結果：

Person {

name: 'xiaoming',

age: 10,

sex: 'man',

code: [Function (anonymous)]

}

Xiaoming is coding

方式二：通過"對象.屬性名"添加屬性和方法

function Fruit(){}
var tomato = new Fruit();
tomato.name = "xihongshi";
tomato.color = "red";
tomato.use = function(){
    console.log(this.name + " can be to eat");
}
console.log(tomato);
tomato.use();

運行結果：

Fruit { name: 'xihongshi', color: 'red', use: [Function (anonymous)] }

Xihongshi can be to eat

方式三：通過"對象['屬性名']"添加屬性和方法

function Fruit(){}
var tomato = new Fruit();
tomato['name'] = "xihongshi";
tomato['color'] = "red";
tomato['use'] = function(){
    console.log(this.name + " can be to eat");
}
console.log(tomato);
tomato.use();

運行結果：

Fruit { name: 'xihongshi', color: 'red', use: [Function (anonymous)] }

Xihongshi can be to eat

方式四：通過 prototype (原型)添加屬性和方法

function Animal(){};
Animal.prototype.foots = 4;
Animal.prototype.weight = 200;
Animal.prototype.hobby = "sing";
Animal.prototype.have = function(){
    console.log("the animal have " + this.foots + " foot");
}
var pig = new Animal();
console.log(pig);
pig.have();// the animal have 4 foot

運行結果：

Animal {}

the animal have 4 foot

方式五：使用Object.assign添加屬性和方法

function Person(name,age,sex){
    this.name = name;
    this.age = age;
    this.sex = sex;
    this.code = function(){
        console.log(this.name + " is coding");
    }
}
var xiaoming = new Person("xiaoming",10,"man");
console.log(xiaoming);// {name: "xiaoming", age: 10, sex: "man", code: ?}
xiaoming.code();// xiaoming is coding   
var xiaoming2 = Object.assign({}, xiaoming, {test1:'demo1', test2:'demo2'}); // 第一個參數(shù)是 目標對象，后面的全是源對象，執(zhí)行完之后返回目標對象
console.log(xiaoming2);// {name: "xiaoming", age: 10, sex: "man", code: ?, test1: 'demo1', test2: 'demo2'}
xiaoming2.code();// xiaoming is coding

運行結果：

Person {

name: 'xiaoming',

age: 10,

sex: 'man',

code: [Function (anonymous)]

}

xiaoming is coding

{

name: 'xiaoming',

age: 10,

sex: 'man',

code: [Function (anonymous)],

test1: 'demo1',

test2: 'demo2'

}

xiaoming is coding

方式六：使用擴展運算符...添加屬性和方法

ES6新增語法，可以將兩個對象合并成一個對象。將多個屬性合并成1個對象。

function Person(name,age,sex){
    this.name = name;
    this.age = age;
    this.sex = sex;
    this.code = function(){
        console.log(this.name + " is coding");
    }
}
var xiaoming = new Person("xiaoming",10,"man");
console.log(xiaoming);// {name: "xiaoming", age: 10, sex: "man", code: ?}
xiaoming.code();// xiaoming is coding   
var xiaoming2 = {...xiaoming, test1:'demo1', test2:'demo2'};
console.log(xiaoming2);// {name: "xiaoming", age: 10, sex: "man", code: ?, test1: 'demo1', test2: 'demo2'}
xiaoming2.code();// xiaoming is coding

運行結果：

Person {

name: 'xiaoming',

age: 10,

sex: 'man',

code: [Function (anonymous)]

}

xiaoming is coding

{

name: 'xiaoming',

age: 10,

sex: 'man',

code: [Function (anonymous)],

test1: 'demo1',

test2: 'demo2'

}

xiaoming is coding