How can you handle multiple Promises concurrently without using `Promise.all()`?

Question

Accepted Answer

Promise.race(): The first resolved Promise (or the first rejected one) will determine the outcome. promise.allSettled : Fulfills when all promises settle. promise.any(). Fulfils when any of the promises are fulfilled; rejects when all of the promises are rejected. const tasks = [fetchUser(), fetchPosts(), fetchAnalytics()]; // Promises started concurrently

// Await each sequentially while they run in parallel in the background
const results = [];
for (const task of tasks) {
  try {
    results.push(await task);
  } catch (err) {
    results.push(null);
  }
} async function mapConcurrent(items, limit, fn) {
  const results = new Array(items.length);
  const executing = new Set();

for (const [index, item] of items.entries()) {
    const p = Promise.resolve().then(() => fn(item, index));
    results[index] = p;
    executing.add(p);

const clean = () => executing.delete(p);
    p.then(clean, clean);

if (executing.size >= limit) {
      await Promise.race(executing); // Wait for any slot to free up
    }
  }

return Promise.allSettled(results);
}

// Example usage: max 2 requests at a time
const urls = ['/url1', '/url2', '/url3', '/url4'];
await mapConcurrent(urls, 2, (url) => fetch(url));

How can you handle multiple Promises concurrently without using `Promise.all()`?

You can either chose in built methods like `allsettled(), race(), any()`.

How can you handle multiple Promises concurrently without using `Promise.all()`?

You can either chose in built methods like `allsettled(), race(), any()`.

How can you handle multiple Promises concurrently without using `Promise.all()`?

You can either chose in built methods like allsettled(), race(), any().

How can you handle multiple Promises concurrently without using `Promise.all()`?

You can either chose in built methods like allsettled(), race(), any().

You can either chose in built methods like `allsettled(), race(), any()`.

You can either chose in built methods like `allsettled(), race(), any()`.