Why are my integers not adding negative values?

Question

Really confused here.

NSInteger iteration;
NSInteger direction;

- (void)pulse {
    self.position = ccpAdd(self.position, vectors[iteration]);
    iteration = iteration + direction;
    if (iteration >= totalIterations) {
        direction = -1;
        iteration = totalIterations - 1;
    } else if (iteration < 0) {
        direction = 1;
        iteration = 0;
    }
}

What's happening is once iteration exceeds totalIterations, iteration never goes back below. When the loop comes around again, po iteration shows it as equal to totalIterations.

AFAIK I'm not adding it elsewhere.

Am I missing something? Something to do with NSInteger?

Where are `iteration` and `direction` defined? Where are they initialized? — trojanfoe, Mar 10 '15 at 16:27
Top of the implementation. I don't initialize them.. they start as 0 — quantumpotato, Mar 10 '15 at 16:28
Which makes them class variables. Are there more than one instance of the class? — trojanfoe, Mar 10 '15 at 16:28
How are they class variables? They are under @implementation — quantumpotato, Mar 10 '15 at 16:32
You need to put them in @interface as properties for them to be instances variables, right? — Alex, Mar 10 '15 at 18:14
@Alex No. Don't confuse ivars and properties. ivars can be out in one of 3 places. The interface, the class extension, or the implementation. In all three cases they must be inside the curly braces. — rmaddy, Mar 10 '15 at 19:23
@quantumpotato they must be in the curly braces of the `@implementation` to be ivars. If not in the curly braces they become global variables. — rmaddy, Mar 10 '15 at 19:25

score 0 · Answer 1 · answered Mar 10 '15 at 21:10

0

Subclass had the same instance variable name as the parent class.. the parent class was incrementing this instance variable.

answered Mar 10 '15 at 21:10

quantumpotato

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Why are my integers not adding negative values?

1 Answers1