Maximum Call Stack Size Exceeded During a setTimeout Call

Question

I'm trying to call my function every 4 seconds so it will increment a number live. For some reason I keep getting errors. Here's my code:

<html>
<head>
<title>Recycle Counter</title>
<script type="text/javascript">
    function rand(from, to)
    {
       return Math.floor(Math.random() * (to - from + 1) + from); // Generates random number
    }   

    var num = rand(10000, 100000);

    function getNum() // Gets triggered by page load so innerHTML works
    {
        document.getElementById('counter').innerHTML = num + 7;
        setTimeOut(getNum(), 4000);
    }   
</script>
</head>
<body onload="getNum()">
    <div id="counter">

    </div>
</body>
</html>

You realize that your function getNum() will get stuck in an endless recursive loop right? — maple_shaft, Jan 04 '12 at 18:20

Rob W · Accepted Answer · 2012-01-04T18:24:41.737

42

Inside getNum, you're directly invoking the getNum function, causing the stack to exhaust. Replace the function call getNum() with the function reference getNum:

function getNum() // Gets triggered by page load so innerHTML works
{
    num += 7;     // Increase and assign variable
    document.getElementById('counter').innerHTML = num;
    setTimeout(getNum, 4000);   // <-- The correct way
}

Link to documentation of setTimeout.

edited Jan 04 '12 at 18:24

answered Jan 04 '12 at 18:18

Rob W

328,606
78
779
666

1

Ha! yeah that got rid of the error but that didn't make it start incrementing. Ima keep at it thanks! – Howdy_McGee Jan 04 '12 at 18:20
1

Now it increases. You have to assign the `num` variable. – Rob W Jan 04 '12 at 18:21
2

What if a `getNum` function takes arguments? – parsecer May 20 '18 at 23:21
1

@parsecer You can add them like this: `setTimeout(getNum, 4000, arg1, arg2, arg3, etc)` – ss1 Jun 06 '19 at 19:11

score 10 · Answer 2 · answered Jan 04 '12 at 18:20

10

The problem is your call to setTimeout is invoking getNum instead of scheduling it for execution. This leads to infinite recursion and a stack overflow. Try the following instead

setTimeout(getNum, 4000);

answered Jan 04 '12 at 18:20

JaredPar

703,665
143
1,211
1,438

score 4 · Answer 3 · answered Jan 04 '12 at 18:21

4

setTimeOut should be setTimeout

answered Jan 04 '12 at 18:21

Hogan

65,989
10
76
113

Maximum Call Stack Size Exceeded During a setTimeout Call

3 Answers3

Linked

Related