When we are playing a quiz there is timer running for every question. How can we create this type of timer using javascript?

Answer 1

https://code.sololearn.com/WC9RFzLouVNQ/?ref=app

Answer 2

This is mostly a conceptual answer so that others can deliver code / work with it / use another idea.

JS is event-driven, and only updates the DOM/display when you give up the main thread, so strategies used in other languages (like a tight loop waiting for the time to change, or sleeping for 1 second) would just hang the browser. In JS, if you want something to happen later, send a message using the event system, then drop off the end of your function so events run.

// onload is an event!
document.onload = function {
// set a message 1000ms from now
setTimeout(updateCounter, 1000);

// give up control, events will run
}

// Nothing happens in your code for 1000ms (the engine is busy handling events though)

// JS fires your event 1000ms later and runs this function
function updateCounter() {
...decrement the counter
...update a DOM element
if the counter is above 0:
setTimeout(updateCounter, 1000)

// give up control, events will run again
}