30 Days of Javascript 13 - Sleep

Given a positive integer millis, write an asynchronous function that sleeps for millis milliseconds. It can resolve any value.

Example 1:

Input: millis = 100 Output: 100 Explanation: It should return a promise that resolves after 100ms. let t = Date.now(); sleep(100).then(() => { console.log(Date.now() - t); // 100 }); Example 2:

Input: millis = 200 Output: 200 Explanation: It should return a promise that resolves after 200ms.

/**
 * @param {number} millis
 */
async function sleep(millis) {
  return new Promise((resolve) => {
    setTimeout(() => {
      resolve();
    }, millis);
  });
}

/**
 * let t = Date.now()
 * sleep(100).then(() => console.log(Date.now() - t)) // 100
 */

The function returns a promise, which will resolve after the specified delay. Inside the promise’s executor function, setTimeout is used to introduce the desired delay. Once the timeout completes, the promise is resolved by calling resolve(), indicating that the sleep operation has finished.