<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>promise.all第二遍</title>
</head>
<body>
<script>
function promiseAll(_promises) {
return new Promise((resolve, reject) => {
const promises = [..._promises];
const arr = [];
let count = 1;
for (let i = 0; i < promises.length; i++) {
Promise.resolve(promises[i]).then(
data => {
arr[i] = data;
if (++count === promises.length) {
resolve(arr);
}
},
err => {
reject(err);
}
);
}
});
}
function promiseAll1(_promises) {
return new Promise((resolve, reject) => {
const promises = [..._promises];
const arr = [];
let count = 1;
for (let i = 0; i < promises.length; i++) {
Promise.resolve(promises[i]).then(
data => {
arr[i] = data;
if (++count === promises.length) {
resolve(arr);
}
},
err => {
reject(err);
}
);
}
});
}
function promiseAll2(_promises) {
return new Promise((resolve, reject) => {
const promises = [..._promises];
let count = 1;
const arr = [];
for (let i = 0; i < promises.length; i++) {
Promise.resolve(promises[i]).then(
data => {
arr[i] = data;
if (++count === promises.length) {
resolve(arr);
}
},
err => {
reject(err);
}
);
}
});
}
let a = `回调函数延迟绑定；错误冒泡，返回值穿透`;
</script>
</body>
</html>
