iOS Label Text Based On Timed Function

Question

I've been trying to create a script that sets a timer and reduces a value by 33 each time it runs. In theory the timer should stop itself after 6 runs, but it keeps going and reaches negative values. Is there a reason for this?

-(void)checkValue:(NSTimer *)myTimer{

    if(pplint > 0){
        pplint = pplint-33;
        NSString *ppllefttext = [NSString stringWithFormat:@"%d", pplint];
        peopleleft.text = ppllefttext;
        NSLog(@"Reduced Timer");   
    }
    if(pplint < 0){
        NSLog(@"Stop Timer");
        [myTimer invalidate];
    }
}


- (IBAction)gotocongrats{
    pplint = 198;
    NSString *ppllefttext = [NSString stringWithFormat:@"%d", pplint];
    peopleleft.text = ppllefttext;
    NSTimer * myTimer = [NSTimer scheduledTimerWithTimeInterval:1
                                                     target:self
                                                   selector:@selector(checkValue:)
                                                   userInfo:nil
                                                    repeats:YES];
    NSLog(@"Started Timer");
}

Answer 1

I took you code and edited it a bit and it works just fine for me.

-(void)checkValue:(NSTimer *)myTimer{

if(pplint > 0){
    pplint = pplint-33;

    NSLog(@"%i",pplint);
    NSLog(@"Reduced Timer");   
}
if(pplint <= 0){
    NSLog(@"Stop Timer");
    [myTimer invalidate];
    }
}

- (IBAction)gotocongrats{
pplint = 198;


NSTimer * myTimer = [NSTimer scheduledTimerWithTimeInterval:1
                                                     target:self
                                                   selector:@selector(checkValue:)
                                                   userInfo:nil
                                                    repeats:YES];
NSLog(@"Started Timer");
}