Promise.all的实现

1. bigfrontend.dev/zh/problem/…

 * @param {Array<any>} promises - notice input might have non-Promises
 * @return {Promise<any[]>}
 */
async function all(promises) {
  // your code here
  const result = []
  for await (let res of promises)
    result.push(res)
  return result
}

2. bigfrontend.dev/zh/problem/…

/**
 * @param {Array<any>} promises - notice input might have non-Promises
 * @return {Promise<any[]>}
 */
async function all(promises) {
  const results = [];

  for (let promise of promises) {
    results.push(await promise);
  }

  return results;
}

3. zhuanlan.zhihu.com/p/41502945 基于promise的版本，该链接提供的实现有问题，但思路是对的，先放这里，以后完善

demo:

let resList = [1,2,3,4,5].map((id)=>{
return fetch(`https://jsonplaceholder.typicode.com/users/${id}`).then(res => res.json())
})

async function all(promises) {
  const results = [];

  for (let promise of promises) {
    results.push(await promise);
  }

  return results;
}
all(resList).then(console.log)