JavaScript setInterval and clearInterval not working

Question

I am trying to use setInterval and clearInterval in literally the simplest case possible:

var passiveInterval = "";
var activeInterval = "";

function myStartFunction()
{
    ...
    passiveInterval = window.setInterval(passiveCheck, pIntAmt);
    activeInterval = window.setInterval(activeCheck, aIntAmt);
    ...
}

function myEndFunction()
{
    ...
    if (passiveInterval != "")
    {
        alert("passiveInterval: " + passiveInterval);
        window.clearInterval(passiveItnerval);
        passiveInterval = "";
    }
    if (activeInterval != "")
    {
        window.clearInterval(activeInterval);
        activeInterval = "";
    }
    ...
}

The incredible thing is that the alert triggers, and gives me the correct value of the interval (an integer), but then the clearInterval statement triggers:

ReferenceError: Can't find variable: passiveItnerval

I have tried this with every permutation of window and this slapped on the front of everything, but nothing works...

What is `passiveCheck` and when does `myEndFunction` get called? — James Montagne, Feb 21 '12 at 02:17
`setTimeout` and `setInterval` return a +ve integer, so it is probably preferable to write: `if (passiveInterval) { /* clear timout */ }` rather than comparing with *empty string*. — RobG, Feb 21 '12 at 02:27
@RobG That's a good idea, thanks. Also, is there any way to feel more like a tool than to post a typo here? > — Maxwell Collard, Feb 21 '12 at 02:30

score 2 · Answer 1 · answered Feb 21 '12 at 02:17

2

Typo. crtl+f for "passiveItnerval"... the "t" and "n" are reversed.

Also, please consider using setTimeout instead of setInterval if possible. setInterval can get hairy.

answered Feb 21 '12 at 02:17

Dagg Nabbit

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What's the best way of doing a recurring timer with `setTimeout` rather than `setInterval`? – Maxwell Collard Feb 21 '12 at 02:22
@MaxwellCollard just set another timeout at the end of the function triggered by the first timeout, and don't set another one instead of using clearInterval. – Dagg Nabbit Feb 21 '12 at 02:23
There's a [campaign to clean up Stack Overflow](http://meta.stackexchange.com/q/167342/187073) by removing these typo-related questions - we could really use your help! Would you mind pitching in a little by casting a close vote on this question? – VisioN Feb 28 '13 at 18:40

score 0 · Answer 2 · answered Feb 21 '12 at 02:18

0

You've got a typo

passiveItnerval != passiveInterval

answered Feb 21 '12 at 02:18

GoldenNewby

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Oh God someone please shoot me, I spent three hours scouring through my whole codebase to fix this... OK, next question, what's the best IDE for JS? Cause Dreamweaver obviously dies. – Maxwell Collard Feb 21 '12 at 02:20
2

Give notepad++ a shot if you are windows. I use Komodo Edit 6 – GoldenNewby Feb 21 '12 at 02:21
or go for NetBeans, cross platform compatible. – mauris Feb 21 '12 at 02:22
Any JetBrains IDE, it would pick this up in a heartbeat. – Cobby Feb 21 '12 at 03:02

score 0 · Answer 3 · answered Feb 21 '12 at 02:38

I have a simple function for this and you can use it over and over again:

var timer = function(t,i,d,f,fend,b) 
{
  if( !f )
   { return; }
  if( t == -1 || t > 0 )
   { setTimeout( function() { b=(f())?1:0; timer( (b)?0:(t>0)?--t:t, i+((d)?d:0), d, f, fend,b ); }, (b||i<0)?0.1:i ); }
  else if( typeof fend == 'function' )
        { setTimeout( fend, 1 ); }
};

parameters:
t = times/repeat count (-1 is endless)
i = interval wait period in milliseconds
d = Interval increase or decrease after each interval 
f = function to call after interval
fend = function to call when t ended

NOTE: when function f() returns true loop can be stopped even when it is endless

very simple to use:

timer(4,1000,0,function(){alert('called');},function(){alert('Thank you - finished');});

Imagine what you can do with it, it is endless ;-)

Greetz and cheers, Erwin Haantjes

JavaScript setInterval and clearInterval not working

3 Answers3