Promise4

作者: 加冰宝贝 | 来源:发表于2018-06-21 20:34 被阅读0次

Promise4

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
// catch
//   它的可以和then的第二个参数一样，用来指定reject的回调
    function cook() {
        console.log("开始做饭");
        let p =new Promise((resolve,reject) => {
            setTimeout(()=>{
                console.log("做饭完毕")
                reject("鸡蛋炒饭，炒糊了")
            },1000)
        })
        return p;
    }
    // 开始吃饭
    function eat(data) {
        console.log("开始吃饭"+data);
        let p =new Promise((resolve,reject) => {
            setTimeout(()=>{
                console.log(data+",吃完了")
                resolve("一双筷子一个碗")
            },1000)
        })
        return p;
    }
    // 开始刷碗
    function wash() {
        console.log("开始刷碗"+data);
        let p =new Promise(resolve => {
            setTimeout(()=>{
                console.log(data+",刷完了")
                resolve("干净的碗筷！")
            },2000)
        })
        return p;
    }
    cook()
        .then(eat)
        .then((err)=>{
            console.log(err)
        })
</script>
</body>
</html>