JS Getter 与 Setter DAY71

Setter 与 Setter
Getter: 取得特定值的方法
Setter: 存值的方法

Getter

var wallet = {    total: 100,    set save(price){        this.total = this.total + price / 2    }}wallet.save = 300;console.log(wallet.total); // 250

Getter + Setter

var wallet = {    total: 100,    set save(price){        this.total = this.total + price / 2    },    get save(){        return this.total / 2;    }}wallet.save = 300;console.log(wallet.save); // 125

另一种定义方式(Object.defineProperty)
但要注意
如果用 defineProperty 去定义getter , setter
则 enumerable , configurable 预设为false

var wallet = {    total: 100,}Object.defineProperty(wallet,'save',{    configurable: true,    enumerable: true,    set : function(price){        this.total = this.total + price / 2;    },    get : function(){        return this.total / 2;    }})wallet.save = 300;console.log(wallet);

这里在举一个例子

var a = [1,2,3];Object.defineProperty(Array.prototype,'latest',{    get: function(){        return this[this.length - 1]    }})console.log(a.latest);

那今天的介绍就到这里
若有任何问题 或 内容有误
都可以跟我说唷