Wait 5 seconds before executing next line

javascript

async-await

promises

nodejs

byAlex Kataev·Aug 9, 2024

Here's the simplest way to delay code execution by 5 seconds in JavaScript:

setTimeout(() => {
  // Mad world... but at least it waited for 5 seconds
}, 5000);

setTimeout() is our hero here, delaying code execution by the specified milliseconds.

More than a `setTimeout`: async/await

Stepping up our game, async/await comes into play. This gives your asynchronous operations a synchronous appearance. Here's how:

// A valuable life skill: learning to wait
function wait(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

async function delayedOperation() {
  console.log('Just wait for it...');
  await wait(5000);
  console.log('5 seconds later, the world is still turning');
}

delayedOperation();

This neat combo of async/await and Promise enhances error handling, improves readability, and tames asynchronous beasts.

Mind these when delaying code

Race conditions are a coder's nightmare

In the thrilling world of asynchronous JavaScript, you must avoid race conditions. If tasks don't wait for each other, like unruly kids, they might cause problems. So, keep track of your tasks and avoid potential clashes.

The question of compatibility

If you are in a relationship with an Old School Browser, remember that it might not embrace async/await. For these old souls, polyfills or transpilers might be necessary to keep things rolling smoothly.

Keep your functions clean

Marie Kondo would approve this: clear old timeouts with clearTimeout() to avoid leftover code mess. A reusable delay function can be your go-to housekeeping tool.

Handling sequential operations and state changes

Avoid a domino effect with chained delays or state changes. Make sure to correctly incorporate the delay:

async function handleStateChange(newState) {
  await wait(5000);
  // Wow, newState! Did you do something new with your bits?
}

Test rigorously to account for the capricious nature of asynchronous operations.

Node.js delayed operations using timers/promises

For the Node.js folks, there's a native solution to use setTimeout in async/await style:

const { setTimeout: wait } = require('timers/promises');

async function nodeSpecificAction() {
  await wait(5000);
  console.log('This Node has been patiently waiting for 5 seconds. Applause! 👏');
}