编辑代码

Promise.prototype.all = function(iterators){
    const promiseArr = Array.from(iterators)
    const len=promiseArr.length
    let count = 0
    let res = []
    return new Promise((resolve,reject)=>{
        promiseArr.forEach((p,index)=>{
            Promise.resolve.then(res=>{
                count++
                res[index]=res
                if(count==len) resolve(res)
            }).catch(e=>{
                reject(e)
            })

        })
    })

}

var p1 = Promise.resolve('2222')
var p2 = new Promise((resolve,reject)=>{
    setTimeout(()=>{
        resolve('p2')
    },1000)
})
var p3 = new Promise((resolve,reject)=>{
    setTimeout(resolve,2000,'p3')
})

Promise.all([p1,p2,p3]).then(res=>{
    console.log(res)
},err=>{
    console.log(err)
})