Implementing Delay/Sleep in JavaScript with Promises and Async/Await

Sometimes, you need to pause execution in JavaScript, like waiting for an API response or adding a delay between actions. Here’s how you can implement a delay (or sleep) function using modern JavaScript.

Using Promises

The setTimeout function is great for delays. Combine it with promises to create a reusable delay function:

function delay(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

This function resolves the promise after the specified time in milliseconds (ms).

Using Async/Await

With async/await, you can make the delay work like a synchronous pause inside asynchronous functions:

async function example() {
  console.log('Start');
  await delay(2000); // Pause for 2 seconds
  console.log('End');
}
example();

Key Points:

• delay(ms) returns a promise that resolves after ms milliseconds.
• await pauses execution in an async function until the promise resolves.

Why Use This Method?

It’s clean, modern, and avoids callback hell. Perfect for developers looking to write readable asynchronous code.

Got questions? Drop them below!