Question

Sorry for the newbie question, but i cannot find an answer to it.

I have a simple operation. I declare a variable, and then i want to loop through an array of integers and add these to the variable. However, i can’t seem to find how to get a += equivalent going in Objective C.

Any help would be awesome.

Code:

NSInteger * result;
for (NSInteger * hour in totalhours)
{
    result += hour; 
}

Answer 1

NSInteger is not a class, it’s a typedef for int. You cannot put it into collections like NSArray directly.

You need to wrap your basic data types (int, char, BOOL, NSInteger (which expands to int)) into NSNumber objects to put them into collections.

NSInteger does work with +=, keep in mind that your code uses pointers to them, which is probably not what you want anyway here.

So

NSInteger a = 1, b = 2; 
a += b; 

would work.

If you put them with [NSNumber numberWitInt:a]; etc. into an NSArray, this is not that easy and you need to use -intValue methods to extract their values first.