I have just started to learn javascript today and i'm trying to work out how i can convert seconds to milliseconds.

I tried to find something that would help me but everything i find is converting milliseconds to minutes or hours.

let str = 'You must wait 140 seconds before changing hands';
let timer = 0;
let num = str.match(/\d/g).join("");
timer = num;

console.log(timer);

setTimeout(() => {
  console.log('time done')
}, timer);

I have just started to learn javascript today and i'm trying to work out how i can convert seconds to milliseconds.

I tried to find something that would help me but everything i find is converting milliseconds to minutes or hours.

let str = 'You must wait 140 seconds before changing hands';
let timer = 0;
let num = str.match(/\d/g).join("");
timer = num;

console.log(timer);

setTimeout(() => {
  console.log('time done')
}, timer);

I'm trying to extract the numbers from string and convert it to milliseconds for a setTimeout.

• javascript

• 6 There are 1000ms to a second, so simply multiply the number by 1000 – David Thomas Commented Jan 11, 2022 at 12:38
• 3 1s = 1000ms, so why not to use setTimeout(..., num * 1000) ? – Xeelley Commented Jan 11, 2022 at 12:38
• 1 Does this help you : stackoverflow./questions/43960824/… – Keivan Soleimani Commented Jan 11, 2022 at 12:39

3 Answers 3

• Here is a better regex /(\d+) seconds?/ - the ? means the s is optional
• 1 second is 1000 milliseconds as the word tells us

let str = 'You must wait 140 seconds before changing hands';
let timer = str.match(/(\d+) seconds?/)[1]*1000; // grab the captured number and multiply by 1000
console.log(timer)
setTimeout(() => {
  console.log('time done')
}, timer);

Here is a countdown

let str = 'You must wait 10 seconds before changing hands';
const span = document.getElementById("timer");
let tId = setInterval(() => {
  let timeLeft = +str.match(/(\d+) seconds?/)[1]; // optional s on seconds
  if (timeLeft <= 1) {
    str = "Time's up";
    clearInterval(tId);
  }  
  else str = str.replace(/\d+ seconds?/,`${--timeLeft} second${timeLeft == 1 ? "" : "s"}`)
  span.innerHTML = str;
}, 1000);

<span id="timer"></span>

let str = 'You must wait 140 seconds before changing hands';
let seconds = /\d+/.exec(str)[0];
// milliseconds = seconds * 1000;
const ms = seconds * 1000;

setTimeout(
 () => {// doSomething},
 ms
);
``

If you are getting timestamps in seconds, convert that into milliseconds so that you can change in date format.

Example

let secToMilliSec = new Date(1551268800 * 1000);
let millToDate = new Date(secToMilliSec);
// Wed Feb 27 2019 17:30:00 GMT+0530 (India Standard Time)