Is an NSUInteger equivalent to a plain old int?

Question

I'm just learning. In this tutorial, they've declared a block that takes NSUInteger arguments, and then they simply pass in 6 and 4 . . . I was under the impression all these NS things are object wrappers, different from the built-in c-types.

Now that I'm writing this, I remember them saying earlier that we didn't need the * in NSUInteger declarations because it wasn't like the other NS objects.

But...an NSUInteger is obviously not a c-type. So...what's going on here?

NSUInteger *is* a plain old integer type, but it may not be identical to `unsigned int`. — Greg Parker, Mar 05 '14 at 05:48
As you are seeing, not everything that begins with `NS` is a class. Some are typedefs for primitive types. — rmaddy, Mar 05 '14 at 06:33

score 2 · Accepted Answer · answered Mar 05 '14 at 05:11

Short Answer: Sometimes, NSUInteger is "unsigned int". But sometimes it is not. It depends the platform you compile your code.

Long Answer:

NSUInteger or NSInteger is defined in the NSObjCRuntime.h, you can Command+click on an NSUInteger and see the define below:

#if __LP64__ || (TARGET_OS_EMBEDDED && !TARGET_OS_IPHONE) || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
typedef unsigned long NSUInteger;
#else
typedef int NSInteger;
typedef unsigned int NSUInteger;
#endif

So, generally speaking, it means in a 64-bit environment, NSUInteger is an alias of unsigned long, while in a 32 bit environment, it is an int.

Because the new iPhone 5s is running on a 64-bit CPU, so it is recommended to use NSUInteger or NSInteger instead the plain unsign int or int.

And at last, NSUInteger is a real c-type indeed, in another name so the complier can do some work for you to handle it better.

score 1 · Answer 2 · edited May 23 '17 at 12:06

1

NSUInteger is like unsigned integer NSInteger is like int

See

When to use NSInteger vs. int

edited May 23 '17 at 12:06

Community

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answered Mar 05 '14 at 05:06

user4951

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score 1 · Answer 3 · answered Mar 05 '14 at 05:09

If, in XCode, you option-Click on NSInteger you'll go to the definition:

#if __LP64__ || TARGET_OS_EMBEDDED || TARGET_OS_IPHONE || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
typedef unsigned long NSUInteger;
#else
typedef int NSInteger;
typedef unsigned int NSUInteger;
#endif

So for 64-bit systems, it is defined as long, not as int.

Is an NSUInteger equivalent to a plain old int?

3 Answers3