Implement Promise.all Example

Question

Create multiple promises and use Promise.all() to execute them together. Display all resolved results once every promise is completed.

Coding Answer

const promise1 = new Promise((resolve) => {
  setTimeout(() => {
    resolve("API Data");
  }, 1000);
});

const promise2 = new Promise((resolve) => {
  setTimeout(() => {
    resolve("User Data");
  }, 2000);
});

const promise3 = new Promise((resolve) => {
  setTimeout(() => {
    resolve("Product Data");
  }, 1500);
});

Promise.all([promise1, promise2, promise3])
  .then((results) => {
    console.log(results);
  })
  .catch((err) => {
    console.log(err);
  });

Preview

[
  'API Data',
  'User Data',
  'Product Data'
]

Explanation

Promise.all() executes multiple promises together
It waits until all promises are resolved
If one promise fails → Promise.all() rejects immediately
Results are returned in array format
Useful for parallel async operations