Promise-01 三种状态

作者: 呆桃冲鸭冲鸭 | 来源:发表于2020-09-10 20:30 被阅读0次

Promise-01 三种状态
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三种状态

三种状态：

pending
fulfilled
rejected

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>my</title>
</head>
<body>
    <p>test my</p>
</body>
<script type="module">
    import MyPromise from './promise.js';
    // 三种状态 1.pending 2.fulfilled 3.rejected
    let myP = new MyPromise((resolve,reject)=>{
        // resolve("suc");
        reject("err");
    });
    console.log(myP);

</script>
</html>

promise.js:
export default class MyPromise{
    constructor(handle){
        this.state = "pending";
        this.result = undefined;

        // handle(function(val){
        //     // resolve
        //     this.state = "fulfilled";
        //     this.result = val;
        // }.bind(this),function(val){
        //     // rejected
        //     this.state = "rejected";
        //     this.result = val;
        // }.bind(this));

        // handle((val)=>{
        //     // resolve
        //     this.state = "fulfilled";
        //     this.result = val;
        // },(val)=>{
        //     // rejected
        //     this.state = "rejected";
        //     this.result = val;
        // });

        handle(this._resolve.bind(this),this._reject.bind(this));
    };
    _resolve(val){
        this.state = "fulfilled";
        this.result = val;
    }；
    _reject(val){
        this.state = "rejected";
        this.result = val;
    }；
}

打印结果