关于javascript:手写一个promise的过程一

const PEDDING = 'PEDDING';const RESOLVE = 'RESOLVE';const REJECT = 'REJECT';// promise 有三种状态class NewPromise {// 初始状态为 PEDDING    status = PEDDING    result = undefined;    reason = undefined;    // 公布订阅者模式    // 目标是为了实现异步    onResolveArr = [];    onRejectArr = [];    constructor(exc) {        const resolve = result => {            if (this.status === PEDDING) {                this.result = result                this.status = RESOLVE                // 执行订阅者                this.onResolveArr.map(fn => fn())            }        }        const reject = reason => {            if (this.status === PEDDING) {                this.reason = reason                this.status = REJECT                // 执行订阅者                this.onRejectArr.map(fn => fn())            }        }        exc(resolve, reject)    }    then(onResolve, onReject) {        if (this.status === RESOLVE) {            setTimeout(() => {                onResolve(this.result)            }, 0)        }        if (this.status === REJECT) {            setTimeout(() => {                onReject(this.reason)            }, 0)                   }        // 公布订阅者模式        if (this.status === PEDDING) {            // 将发布者增加到数组外面            this.onResolveArr.push(() => {                onResolve(this.result)            })            this.onRejectArr.push(() => {                this.onReject(this.reason)            })        }    }}// let yan = new Promise((resole, reject) => {//     resole('闫大爷真帅')// })// yan.then(res => {//     console.log(res)// })let newYan = new NewPromise((resole, reject) => {    setTimeout(()=>{        resole('new闫大爷真帅')    },3000)    })newYan.then(res => {    console.log(res)})console.log(11111111)