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I'm having a really weird problem here with NSUInteger in iOS7,

everything is perfect before iOS7, I guess it's related to the 64-bit support in iOS7.

My code is like this, very simple:

if (blah blah blah) {
    NSUInteger firstRow = 0;
    firstRow = ([self.types containsObject:self.selectedMajorType] ?
        [self.types indexOfObject:self.selectedMajorType] + 1 : 0);
    ...
}

According to my console,

[self.types containsObject:self.selectedMajorType] is true

[self.types indexOfObject:self.selectedMajorType]+1 is 1,

no doubt, and indexOfObject also returns an NSUInteger (according to Apple's document),

here's the screenshot: enter image description here but firstRow is always fking **0

This is so creepy I don't know what's going on with NSUInteger,

can someone help me? Thanks a lot!!

____new finding____ enter image description here

I guess this is the problem? It's weird..

Wang Liang
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    At what point in the execution do you print `firstRow`? – rmaddy Jun 05 '14 at 04:32
  • Hi, I printed these right after the code above – Wang Liang Jun 05 '14 at 12:05
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    Are you sure it's not optimized out? Try printing everything using `NSLog` and not in the debugger. – Daniel Jun 05 '14 at 12:12
  • Try to put parenthesis around ([self.types indexOfObject:self.selectedMajorType]+1) the problem might be due to precedence of operations – Andrea Jun 05 '14 at 12:23
  • Hi @Dani, thanks for your comment! I used NSLog and it is 1 now. I guess it's optimized out. Could you please tell me more about the stuff? is it a feature of xcode? thanks! – Wang Liang Jun 05 '14 at 12:31
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    @Eno: To ease debugging you can [turn off optimization in build settings](http://stackoverflow.com/a/18472604/362589). This is a feature of the compiler Xcode is using. – Daniel Jun 05 '14 at 13:56

1 Answers1

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I tried to recreate this scenario but I was always getting the expected result 1.

Here is the screen shot:

enter image description here

Here is the project, try running this and see if you still face the problem.

PS. I was using xcode 5.1 and iPhone 64bit Simulator.

=============UPDATE================

Here are some explanations on the lldb commands you used.

po : prints the objective C description of an object.

print / p : Evaluates a generalized expression in the current frame. Specify return type of the function if not used in your program.

Hope this screenshot will help you understand more.

enter image description here

Aditya Sinha
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