Objective-C/C++ constants

Question

Hi,

EDIT: My example might have created some confusion. I have changed the example below to reflect what I want to achieve. Hope this is more clear.

I am trying to define a constant in my objective-c code. I am using the standard #define to do this. Eg:

#define bluh "a"

I would like to define another constant like this

#define blah bluh +@"b"

The compiler throws up an error (rightly so) "invalid operands to binary +". How can I get this to work? Thanks for the help.

I also tried the Objective-C way like this:

NSString *const A =@"a";
NSString *const B = [NSString stringWithFormat:@"%@%@",A,@"b"];

But this gives me another error "Initializer element is not constant" Any help will be appreciated.

Cheers,

Answer 1

http://stackoverflow.com/questions/538996/constants-in-objective-c

Answer 2

I don't know objective C. In C++, adjacent string literals are concatenated, so it's adequate to use:

#define blah bluh "b"

BTW / it's standard practice to use uppercase for preprocessor defines wherever possible, and for no other purpose, minimising the chance of unexpected substitutions.

Answer 3

In standard c/c++ you can concatenate literal strings by just placing them next to each other e.g. "string one-" "string two" will become "string one-string two" after the compiler has its way with it.

Not sure if this will work with the '@' symbol you've got at the start, but just try doing:

#define bluh "a"
#define blah bluh @"b"

Haven't had that much experience with Objective-C, but hopefully they kept this part inter operable.