Stop setInterval call in JavaScript

Question

I am using setInterval(fname, 10000); to call a function every 10 seconds in JavaScript. Is it possible to stop calling it on some event?

I want the us

Answer 1

In nodeJS you can you use the "this" special keyword within the setInterval function.

You can use this this keyword to clearInterval, and here is an example:

setInterval(
    function clear() {
            clearInterval(this) 
       return clear;
    }()
, 1000)

When you print the value of this special keyword within the function you outpout a Timeout object Timeout {...}

Answer 2

var keepGoing = true;
setInterval(function () {
     if (keepGoing) {
        //DO YOUR STUFF HERE            
        console.log(i);
     }
     //YOU CAN CHANGE 'keepGoing' HERE
  }, 500);

You can also stop the interval by adding an event listener to let's say a button with the ID "stop-interval":

$('buuton#stop-interval').click(function(){
   keepGoing = false;
});

HTML:

<button id="stop-interval">Stop Interval</button>

Note: The interval will still be executed, nothing will happen though.

Answer 3

The answers above have already explained how setInterval returns a handle, and how this handle is used to cancel the Interval timer.

Some architectural considerations:

Please do not use "scope-less" variables. The safest way is to use the attribute of a DOM object. The easiest place would be "document". If the refresher is started by a start/stop button, you can use the button itself:

<a onclick="start(this);">Start</a>

<script>
function start(d){
    if (d.interval){
        clearInterval(d.interval);
        d.innerHTML='Start';
    } else {
        d.interval=setInterval(function(){
          //refresh here
        },10000);
        d.innerHTML='Stop';
    }
}
</script>

Since the function is defined inside the button click handler, you don't have to define it again. The timer can be resumed if the button is clicked on again.

Answer 4

Why not use a simpler approach? Add a class!

Simply add a class that tells the interval not to do anything. For example: on hover.

var i = 0;
this.setInterval(function() {
  if(!$('#counter').hasClass('pauseInterval')) { //only run if it hasn't got this class 'pauseInterval'
    console.log('Counting...');
    $('#counter').html(i++); //just for explaining and showing
  } else {
    console.log('Stopped counting');
  }
}, 500);

/* In this example, I'm adding a class on mouseover and remove it again on mouseleave. You can of course do pretty much whatever you like */
$('#counter').hover(function() { //mouse enter
    $(this).addClass('pauseInterval');
  },function() { //mouse leave
    $(this).removeClass('pauseInterval');
  }
);

/* Other example */
$('#pauseInterval').click(function() {
  $('#counter').toggleClass('pauseInterval');
});

body {
  background-color: #eee;
  font-family: Calibri, Arial, sans-serif;
}
#counter {
  width: 50%;
  background: #ffffd;
  border: 2px solid #009afd;
  border-radius: 5px;
  padding: 5px;
  text-align: center;
  transition: .3s;
  margin: 0 auto;
}
#counter.pauseInterval {
  border-color: red;  
}

<!-- you'll need jQuery for this. If you really want a vanilla version, ask -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>


<p id="counter">&nbsp;</p>
<button id="pauseInterval">Pause</button></p>

I've been looking for this fast and easy approach for ages, so I'm posting several versions to introduce as many people to it as possible.

Answer 5

Already answered... But if you need a featured, re-usable timer that also supports multiple tasks on different intervals, you can use my TaskTimer (for Node and browser).

// Timer with 1000ms (1 second) base interval resolution.
const timer = new TaskTimer(1000);

// Add task(s) based on tick intervals.
timer.add({
    id: 'job1',         // unique id of the task
    tickInterval: 5,    // run every 5 ticks (5 x interval = 5000 ms)
    totalRuns: 10,      // run 10 times only. (omit for unlimited times)
    callback(task) {
        // code to be executed on each run
        console.log(task.name + ' task has run ' + task.currentRuns + ' times.');
        // stop the timer anytime you like
        if (someCondition()) timer.stop();
        // or simply remove this task if you have others
        if (someCondition()) timer.remove(task.id);
    }
});

// Start the timer
timer.start();

In your case, when users click for disturbing the data-refresh; you can also call timer.pause() then timer.resume() if they need to re-enable.

See more here.

Answer 6

The clearInterval() method can be used to clear a timer set with the setInterval() method.

setInterval always returns a ID value. This value can be passed in clearInterval() to stop the timer. Here is an example of timer starting from 30 and stops when it becomes 0.

  let time = 30;
  const timeValue = setInterval((interval) => {
  time = this.time - 1;
  if (time <= 0) {
    clearInterval(timeValue);
  }
}, 1000);