# 如何实现一个 promise.any
Issue
欢迎在 Gtihub Issue 中回答此问题: Issue 499 (opens new window)
Author
Promise.any 的行为跟 Promise.all 刚好相反
Promise.any = (promiseArray) => {
return new Promise((resolve, reject) => {
const _promiseArray = Array.from(promiseArray);
const length = _promiseArray.length;
const rejectedArray = [];
_promiseArray.forEach((item) => {
Promise.resolve(item).then(
(val) => {
resolve(val);
},
(reason) => {
rejectedArray.push(reason);
if (rejectedArray.length === length) {
reject(new AggregateError(rejectedArray));
}
}
);
});
});
};