Question

I’d like to view the value of an NSUInteger at any given time. I assign the value below:

NSUInteger test = -1;

Then try to view it in the debugger:

(gdb) po test
Cannot access memory at address 0xffffffff
(gdb) p test
$1 = 4294967295
Current language:  auto; currently objective-c

Far as I know, it is a value type. Where is -1?

Answer 1

You’re using an NSUInteger, which is unsigned. As such, any negative values assigned will actually be interpreted very large positive values.

You want to use NSInteger which is signed (and therefore can be both positive and negative values). You should then be able to do (gdb) p test to see the value.