<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<script>
//使用settimeout
new Promise((resolve, reject) => {
setTimeout(() => {
resolve()
}, 2000)
}).then(() => {
console.log('hello world')
console.log('hello world')
console.log('hello world')
console.log('hello world')
return new Promise((resolve, reject) => {
setTimeout(() => {
resolve()
}, 1000)
})
}).then(() => {
console.log('hello world')
console.log('hello world')
console.log('hello world')
console.log('hello world')
})
</script>
</body>
</html>
运行结果
