ES6-Symbol的用法 ，symbol在对象中的应用，改变值

es6-symbol的用法，，symbol在对象中的应用，改变值

let a = new string;
let b = new number;
let c = new boolean;
let d = new array;
let e = new object;


//symbol
//声明symbol 
//symbol类型是一个全局的原始类型
let f = symbol();
console.log(typeof(f)) //symbol

let g = symbol('ananiah');
console.log(g)  //symbol(ananiah)
console.log(g.tostring())  //symbol(ananiah) 转为字符串

//symbol在对象中的应用
let ananiah = symbol();
let obj = {
    [ananiah] : '大诶啊'
}
console.log(obj[ananiah]) //大诶啊

//改变值
obj[ananiah] = 'web';
console.log(obj[ananiah]) //web

// 用法
let noage = {name:'ananiah',skill:'eat'};
let age  = symbol();
noage[age] = 18;
console.log(noage) // {name: "ananiah", skill: "eat", symbol(): 18}
for(let item in noage){
    console.log(noage[item])  //ananiah eat 
}
console.log(noage[age]) // 18