# Is the FMOD\_Channel\_IsPlaying() always guaranteed to work properly?
**URL:** https://qa.fmod.com/t/is-the-fmod-channel-isplaying-always-guaranteed-to-work-properly/19315
**Category:** FMOD Engine
**Tags:** cpp
**Created:** [September 26, 2022, 9:24am UTC](https://qa.fmod.com/t/is-the-fmod-channel-isplaying-always-guaranteed-to-work-properly/19315 "2022-09-26T09:24:27Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@jiyongman](https://qa.fmod.com/u/jiyongman)
#### Post date: [September 26, 2022, 9:24am UTC](https://qa.fmod.com/t/is-the-fmod-channel-isplaying-always-guaranteed-to-work-properly/19315/1 "2022-09-26T09:24:27Z")
Do I need to set the value of the variable **isPlaying** to 0 before calling `FMOD_Channel_IsPlaying(myChannel, &isPlaying)`?
A long time ago when I used the function of the older **FMOD Ex** version, it always returned “true”.
It caused very serious bugs in our app back then, and assigning “false” right before the `FMOD_Channel_IsPlaying()` calls solved them.
I still don’t know the exact reason for the bug, but initializing `FMOD_BOOL`s with “false” became my habit ever since.
Is the `FMOD_Channel_IsPlaying()` always guaranteed to return a correct value regardless of whether the variable’s initialized before use?
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### Author:  [@Connor\_FMOD](https://qa.fmod.com/u/Connor_FMOD)
#### Post date: [September 29, 2022, 12:24am UTC](https://qa.fmod.com/t/is-the-fmod-channel-isplaying-always-guaranteed-to-work-properly/19315/2 "2022-09-29T00:24:09Z")
Hi,
The best way to check that FMOD functions have run correctly is to use `FMOD_RESULT`. Most FMOD Functions will return a `FMOD_RESULT` which you can then debug, a full list of the return values can be found under [Core API Reference | Common](https://fmod.com/docs/2.02/api/core-api-common.html#fmod_result).
It is a good idea to initialize variables, doing so avoids the possibility of using uninitialized values which may lead to undefined behavior.
Hope this helps!