allSetted实现

本节目标：理解“allSetted实现”的核心思路，并能把它用于实际开发或面试表达。 // polyfills.js if (!Promise.allSettled) { Promise.allSettled = function (promises) { return new Promise(function (resolve) { if (!Array.isArray(promises)) { return resolve([]); } var results = []; var completed = 0; for (let i = 0; i < promises.length; i++) { promises[i] .then(function (value) { results[i] = { status: "fulfilled", value: value }; if (++completed === promises.length) { return resolve(results); } }) .catch(function (reason) { results[i] = { status: "rejected", reason: reason }; if (++completed === promises.length) { return resolve(results); } }); } }); }; } export default null;