异步操作
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script type="text/javascript">
let promise=new Promise((resolve, reject)=>{
//初始化promise状态
setTimeout(()=>{
resolve('厉害');
//reject('抱歉');
console.log('333')
},2000);
console.log('111')
});
console.log('222')
promise
.then((data)=>{//成功的回调
console.log('成功了')
},
(error)=>{//失败的回调
console.log('失败了')
})
</script>
</head>
<body>
</body>
</html>