Javascript - setTimeout/setInterval execute countdown before the function

Question

I have a timer which triggers a function each 3 seconds using setTimeout or setInterval. The point is that I need to execute the countdown before the function instead of execute the function first and then the timer.

This is the code:

var timer;

document.getElementById('myBtn').addEventListener('mousedown', function (){
    timer = setInterval(alert("Ey, release the button!"), 3000);
});

And this should be the order of actions:

Click and hold the button.
Start the countdown ...3, 2, 1...
Trigger the function.

loxxy · Accepted Answer · 2015-11-22 14:57:19Z

2

You could trigger another function at the end of the timer. Since you only need to call it once.. You could just use setTimeout

document.getElementById('myBtn').addEventListener('mousedown', function (){
    alert("Ey, release the button!")
    setTimeout(fireMe, 3000);
});

function fireMe() {
    // Boom
}

You might also want to add clearTimeout on mouseup event.

edited Nov 22, 2015 at 14:57

answered Nov 22, 2015 at 14:50

loxxy

13.2k2 gold badges28 silver badges57 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Zohaib Ijaz · Accepted Answer · 2016-06-23 02:54:43Z

1

Do something like

var timer;

   document.getElementById('myBtn').addEventListener('mousedown', function (){
     timer = setTimeout(function(){
       alert("Ey, release the button!");
     }, 3000);
});

edited Jun 23, 2016 at 2:54

answered Nov 22, 2015 at 14:44

Zohaib Ijaz

23k7 gold badges43 silver badges63 bronze badges

5 Comments

loxxy Over a year ago

Errm.. what's the difference?

Karl-Johan Sjögren Over a year ago

The difference is that the alert-call is wrapped in a function in this code so it will be passed as a callback. In the OPs code it's not so it will be evaluated and then the result from alert will be passed on to setInterval which would be useless.

Zohaib Ijaz Over a year ago

You have to pass a callback inside setInterval function as first argument which is then called after 3000 milliseconds but you executed the statement there.

Morteza Tourani Over a year ago

This will alerts every 3 seconds not once.

Zohaib Ijaz Over a year ago

@mortezaT The whole idea was to tell how to call the alert. However I modified my answer

Collectives™ on Stack Overflow

Javascript - setTimeout/setInterval execute countdown before the function

2 Answers 2

Comments

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related