Understanding setInterval variable value

[Lucy]

I want to check I understand how this works. If I set an interval and assign it to variable a, then put 'a' into console.log and it comes out as '2', that means it's the second interval running on the page, yes?

 

I think I'm not managing to cancel intervals in my code so I've been trying to use this method to understand what's going on. One of my intervals keeps coming out as 2 in Firefox, so I thought, that particular one isn't causing a problem...

 

But then I tested my intervals in Internet Explorer 8, and got these values:

3943428

3943435

3943434

3943432

 

So I wondered if I've gotten the wrong idea about this? There can't possibly be over 2 million intervals running on the page (surely not where there aren't that many in Firefox).

 

(I could happily never use intervals/timeouts ever, ever again at this point....)

Edited April 12, 2015 by Lucy

[davej]

I suspect that the values of these variables are meaningless. You use one variable per timer and you only use the variable to clear the timer it is associated with. You might set the variable to null when you want to remember that the timer is not running.

[Ingolme]

setTimeout() and setInterval() return a positive integer to be used as an identifier for the timer. There's no specification as to what value the number should have aside from being a positive integer. Some browsers may choose to start with 1, while others might decide to use a random number.

[Lucy]

Ah...okay - thanks.

Edited April 14, 2015 by Lucy