Checking whether clearInterval has been called?

Question

Given this code:

bob = setInterval(function, 1000);
clearInterval(bob);

Is there now a way to know if that interval has been cleared?

C

Answer 1

bob only contains an id of the interval used to clear it. When you call clearInterval, it gets the interval associated with that id and clears it. The id isn't changed at all.

see here for demonstration

example:

This will show you the interval's id (returned by setInterval earlier). If you know the interval's id is 1, you can just use clearInterval(1) to clear the interval. So your way of using setting bob to null is a good way of doing it. Just be sure that !bob doesn't return true if the bob happens to be 0. :D