完整代码如下：//定义三种状态constPENDING='pending';//等待constFULFILLED='fulfilled';//成功constREJECTED='rejected';//失败类MyPromise{constructor(executor){try{executor(this.resolve,this.reject);}catch(e){this.reject(e)}}//定义一个属性status=PENDING;//定义两个实例属性，分别表示成功后的值和失败后的原因value=undefined;原因=未定义；//成功回调successCallback=[];//失败回调failedCallback=[];//两个属性，这里定义为箭头函数，因为我们使用的是直接调用，//而普通函数内部的this指向window或者undefined，定义为箭头函数，使得函数内部的this指向类实例对象resolve=value=>{//如果状态不是等待，则阻止程序向下进行if(this.status!==PENDING)return//改变状态为成功this.status=FULFILLED//保存成功值this.value=value;//判断成功回调是否存在，存在则调用//this.successCallback&&this.successCallback(this.value);while(this.successCallback.length){this.successCallback.shift()();}}reject=reason=>{//如果状态不是等待，阻止程序继续下去if(this.status!==PENDING)return//改变状态为失败this.status=REJECTED//Reasonfor保存失败这个。原因=原因；//判断失败回调是否存在，存在则调用//this.failedCallback&&this.failedCallback(this.reason);while(this.failedCallback.length){this.failedCallback.shift()();}}then(successCallback,failedCallback){//可选参数successCallback=successCallback?成功回调：价值=>价值；失败回调=失败回调？failedCallback:原因=>{抛出原因};letpromise2=newPromise((resolve,reject)=>{//状态判断if(this.status===FULFILLED){setTimeout(()=>{try{//定义成功回调返回值，传给接下来的成功回调letsuccessRtn=successCallback(this.value);//判断x的值是普通值还是promise对象//如果是普通值，直接调用resolve//如果是promise对象，检查promsie对象返回的结果//然后判断是否根据promise对象返回的结果调用resolve或reject//执行resolve方法相当于将返回值传递给下一个成功回调函数thenresolvePromise(promise2,successRtn,resolve,reject);}抓住（e）{拒绝（e）；}},0);}elseif(this.status===REJECTED){setTimeout(()=>{try{letfailedRtn=failedCallback(this.reason);resolvePromise(promise2,failedRtn,resolve,reject);}catch(e){reject(e)}},0);}else{//等等，需要保存成功回调和失败回调，需要执行的时候执行this.successCallback.push(()=>{)setTimeout(()=>{try{letsuccessRtn=successCallback(this.value);resolvePromise(promise2,successRtn,resolve,reject);}catch(e){reject(e);}},0);});this.failedCallback.push(()=>{setTimeout(()=>{try{letfailedRtn=failedCallback(this.reason);resolvePromise(promise2,failedRtn,resolve,reject);}catch(e){reject(e)}},0);});}});回报承诺2；};catch(failCallback){this.then(undefined,failCallback)};最后（回调）{返回this.then(value=>{returnMyPromise.resolve(callback()).then(()=>value);},reason=>{returnMyPromise.resolve(callback()).then(()=>{throwreason})})};静态所有（数组）{让??结果=[];//用于判断当前执行值是否等于数组长度，相等时才执行resolve()letidx=0;returnnewMyPromise((resolve,reject)=>{//添加元素方法functionaddElement(index,value){result[index]=value;idx++;if(idx===array.length){resolve(result)}}for(leti=0;i
