How to create a pause of 2 seconds and then execute a line in JS?

Question

Suppose I have a code like this:

console.log(1);
console.log(2);
setTimeout(() => console.log("Callback fired"),2000);
console.log(3);
console.log(4);

What I wanted to have was logging 1 and 2 in console and then waiting for 2 seconds to log "Callback fired" and then carry on.

I did try using promise but that didn't worked either or perhaps I did it wrong

Does this answer your question? [What is the JavaScript version of sleep()?](https://stackoverflow.com/questions/951021/what-is-the-javascript-version-of-sleep) — FZs, Feb 05 '21 at 08:23

score 2 · Answer 1 · answered Feb 05 '21 at 06:20

You have to use async code. Here is an example:

const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));
(async () => {
  //here your code is async
  console.log(1);
  console.log(2);
  await sleep(2000); // sleep for 2 secs
  console.log("timeout over");
  console.log(3);
  console.log(4);
})();

score 0 · Answer 2 · answered Feb 05 '21 at 06:20

You can resolve a Promise inside the callback of setTimeout and await on it in your main logic as below.

(async() => {
  console.log(1);
  console.log(2);
  await awaitThenLog("Callback fired", 2000);
  console.log(3);
  console.log(4);
})();

async function awaitThenLog(message, delay) {
  return new Promise((resolve) => {
    setTimeout(() => {
      console.log(message);
      resolve();
    }, delay);
  });
}

How to create a pause of 2 seconds and then execute a line in JS?

2 Answers2