Question

I was initially thinking that the code below would return 0, my question, is there a function that I can use to only receive zero/positive results here?

NSUInteger pruneSize = 5 - 20; // Returns: -15

Currently I am just checking the result myself, but was wondering if I was missing something simpler.

NSUInteger pruneSize = 5 - 20;
if(pruneSize >= 0) {
    // Do zero/positive Stuff ...
}

Answer 1

pruneSize >= 0 is always true as pruneSize is unsigned. You should get a warning here. You need to change the type to NSInteger, that is the signed integer. If you want to clip the lower value to zero for a signed int then you can do this:

NSInteger pruneSize = 5 - 20; // signed int
pruneSize = pruneSize < 0 ? 0 : pruneSize;