Question

This is the code, it doesn’t work when [unosUpisa release]; and [unosRazlike release]; are entered;

How to properly release those unosUpisa and unosRazlike objects?

-(IBAction) padIliStilja: (id) sender
{
    NSNumber *unosUpisa = [[NSNumber alloc] init];
    NSNumber *unosRazlike = [[NSNumber alloc] init];
    if ([sender tag] == 1)
    {
    unosUpisa = [NSNumber numberWithInt: 162 + [Data variables].zvanja];
    unosRazlike = [NSNumber numberWithInt: 0];
    }
    else if ([sender tag] == 2)
    {
        unosRazlike = [NSNumber numberWithInt: 252 + [Data variables].zvanja];
        unosUpisa = [NSNumber numberWithInt: 0];
    }

    if ([Data variables].upisZaMi == NO)
    {
        [[Data variables].rezultatMi addObject: unosUpisa];
        [[Data variables].rezultatVi addObject: unosRazlike];
    }
    else
    {
        [[Data variables].rezultatVi addObject: unosUpisa];
        [[Data variables].rezultatMi addObject: unosRazlike];
    }

    [self dismissModalViewControllerAnimated: NO];
    [unosUpisa release];
    [unosRazlike release];
}

Answer 1

You have to release every object that you own (you retained, copied, or init/alloced).
The way you release your objects at the end is correct, but, here unosRazlike = [NSNumber numberWithInt: 0];, you assigned unosRazlike another value, without releasing the previous one, and here is a leak.
Also, with this kind of method, you should retain your object.

So :

unosRazlike = ...
// first
[unosRazlike release];
unosRazlike = [[NSNumber numberWithInt: 0] retain];
// ...
[unosRazlike release];

EDIT

-(IBAction) padIliStilja: (id) sender
{
    // this is no matter
    NSNumber *unosUpisa = [[NSNumber alloc] init];
    NSNumber *unosRazlike = [[NSNumber alloc] init];
    if ([sender tag] == 1)
    {
        // don't forget to release them !
        [unosUpisa release]; [unosRazlike release];
        // and to retain (numberWithInt returns autoreleased object
        unosUpisa = [[NSNumber numberWithInt: 162 + [Data variables].zvanja] retain];
        unosRazlike = [[NSNumber numberWithInt: 0] retain];
    }
    else if ([sender tag] == 2)
    {
        // same again
        [unosUpisa release]; [unosRazlike release];
        // and to retain (numberWithInt returns autoreleased object
        unosRazlike = [[NSNumber numberWithInt: 252 + [Data variables].zvanja] retain];
        unosUpisa = [[NSNumber numberWithInt: 0] retain];
    }

    if ([Data variables].upisZaMi == NO)
    {
        [[Data variables].rezultatMi addObject: unosUpisa];
        [[Data variables].rezultatVi addObject: unosRazlike];
    }
    else
    {
        [[Data variables].rezultatVi addObject: unosUpisa];
        [[Data variables].rezultatMi addObject: unosRazlike];
    }

    [self dismissModalViewControllerAnimated: NO];
    [unosUpisa release];
    [unosRazlike release];
}

But just a thought… why initializing ‘blank’ number objects, if you set the value either in the if or in the else part ?

Just declare them

NSNumber *unosRazlike, *unosUpisa;

and set their values in the if/else.