Objective C - Are SystemSoundID's (typedef'd UInt32) automatically assigned 0?

Question

- (void)playAlarmSound:(NSTimer *)theTimer {
    static SystemSoundID soundID/* = 0 */; // ?
    if (!soundID) {
        soundID = [Utilities createSystemSoundIDFromFile:@"beep" ofType:@"caf"];
    }
    ...
}

Is SystemSoundID (which is a UInt32) automatically assigned 0? or should I explicitly assign it? I have to do it this way and test to see if it hasn't been initialized by the Utilities method because it doesn't compile if I just do static SystemSoundID soundID = [Utilities createSystemSoundIDFromFile:@"beep" ofType:@"caf"];. At first I tried assigning it to NULL, but then I realized its not a pointer, so anyway, should I have the = 0 in there or is it redundant?

Answer 1

This question doesn't involve any objective-c features, so the answer is found in the c standard.

C99, section §6.7.8, paragraph 10:

If an object that has static storage duration is not initialized explicitly, then:

...

— if it has arithmetic type, it is initialized to (positive or unsigned) zero;

UInt32 (which itself is just uint32_t) is an arithmetic type. Hence, initialized to zero.