JavaScript Async

Implement Promise.all

mediumJS / TS

Problem Statement

Implement a custom `promiseAll` function that accepts an array of promises (or values) and returns a single Promise that resolves to an array of results, maintaining original order. If any promise rejects, `promiseAll` rejects with that error immediately.

Examples

Example:
const p1 = Promise.resolve(42);
const p2 = new Promise((resolve) => setTimeout(() => resolve('hello'), 100));
promiseAll([p1, p2]).then(console.log); // [42, 'hello']

Includes TypeScript & JavaScript starter code

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