if (!Promise.allSettled) {Promise.allSettled = function (promises) {return new Promise(resolve => {const data = [], len = promises.length;let count = len;for (let i = 0; i < len; i += 1) {const promise = promises[i];promise.then(res => {data[i] = { status: 'fulfilled', value: res };}, error => {data[i] = { status: 'rejected', reason: error };}).finally(() => { // promise has been settledif (!--count) {resolve(data);}});}});}
}

const promise1 = Promise.resolve(3);
const promise2 = new Promise((resolve, reject) => setTimeout(reject, 100, 'foo'));
const promises = [promise2, promise1];Promise.allSettled(promises).then((results) => results.forEach((result) => console.log(result.status)));// expected output:
// "rejected"
// "fulfilled"

if (!Promise.allSettled) {Promise.allSettled = function (promises) {return Promise.all(promises.map(p => Promise.resolve(p).then(res => {return { status: 'fulfilled', value: res }}, error => {return { status: 'rejected', reason: error }})));};
}

function all(promises) {let len = promises.length, res = []// 修正let count = lenif (len) {return new Promise(function (resolve, reject) {for(let i=0; i<len; i++) {let promise = promises[i];promise.then(response => {res[i] = response// 当返回结果为最后一个时// 修正// if (res.length === len) {if (!--count) {resolve(res)}}, error => {reject(error)})}})}
}// test
let p1 = new Promise(function (resolve, reject) {setTimeout(function () {resolve(1)// reject(new Error('error 1'))}, 3000)
})let p2 = new Promise(function (resolve, reject) {setTimeout(function () {resolve(2)}, 2000)
})let p3 = new Promise(function (resolve, reject) {setTimeout(function () {resolve(3)}, 1000)
})all([p1, p2, p3]).then(res => {console.log(res) //(*)
}).catch(console.log)
// 修正前*处
// console:[empty × 2, 3]
// 修正后*处
// console: [1, 2, 3]