index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width,initial-scale=1.0">
<link rel="icon" href="<%= BASE_URL %>favicon.ico">
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>
<title>es6test</title>
</head>
<body>
<noscript>
<strong>We're sorry but es6test doesn't work properly without JavaScript enabled. Please enable it to continue.</strong>
</noscript>
<div id="app"></div>
<script type="module">
// 以前的数据类型只有String、number、Array、Boolean、Object、undefined、function
// 新增数据类型Symbol
// 特点：不能new出来，可用于存放key，私有数据
let aa = Symbol("aaa");
console.log(typeof(aa)); // symbol
console.log(aa); // Symbol(aaa)
let json1 = {
a:"apple",
b:"banana0",
[aa]:"Tom"
}
console.log(json1[aa]); //String
console.log(typeof(json1[aa])); // Tom
// Symbol作为key在for in 中循环不出来
for(let key in json1){
console.log(key); // a b
}
// genarator函数 生成器 解决异步，深度嵌套 async
// 定义
function * show(){
yield 'welcome';
yield 'to';
yield 'here';
yield 'ou';
return '结束了'
}
// 调用
let newShow = show();
// var done = false;
// while(!done){
// var {value,done} = newShow.next();
// console.log(value) // welcome to here ou 结束了
// };
console.log("=======================================");
// for...of没有调用return
for(let val of newShow){
console.log(val); // welcome to here ou
}
// 配合解构和扩展运算符
console.log("=======================================");
let [a,b] = show();
console.log(a,b); // welcome to
let [c,...d] = show();
console.log(c,d); // welcome (3) ["to", "here", "ou"]
console.log(...show()); // welcome to here ou
console.log("=======================================");
//配合Array.from
console.log(Array.from(show())); // (4) ["welcome", "to", "here", "ou"]
</script>
<!-- built files will be auto injected -->
</body>
</html>
