promise all的实现

function myPromiseAll(arr) {
  let result = []
  let count = 1

  return new Promise((resolve, reject) => { 
    for (let i = 0; i < arr.length; i++) {
      Promise.resolve(arr[i]).then(res => {
        // console.log(i)
        result[i] = res
        //  console.log(res)
         if (arr.length == res.length ) {
          resolve (result)
         }
       }, reject)
     } 
  })

}
// let p1 = Promise.resolve(3);
// let p2 = 1337;
// let p3 = new Promise((resolve, reject) => {
//   setTimeout(resolve, 100, 'foo');
// }); 
// myPromiseAll([p1, p2, p3]).then(values => { 
//   console.log(values); // [3, 1337, "foo"] 
// })

let p1 = new Promise((resolve, reject) => { 
  setTimeout(resolve, 1000, 'one'); 
}); 
let p2 = new Promise((resolve, reject) => { 
  setTimeout(resolve, 2000, 'two'); 
});
let p3 = new Promise((resolve, reject) => {
  setTimeout(resolve, 3000, 'three');
});
let p4 = new Promise((resolve, reject) => {
  setTimeout(resolve, 4000, 'four');
});
let p5 = new Promise((resolve, reject) => {
  reject('reject');
});

myPromiseAll([p1, p2, p3, p4, p5]).then(values => { 
  // console.log(values);
}, reason => {
  console.log(reason);// reject
});