Constants in Objective-C

Question

I\'m developing a Cocoa application, and I\'m using constant NSStrings as ways to store key names for my preferences.

I understand this is a good idea b

Answer 1

I am generally using the way posted by Barry Wark and Rahul Gupta.

Although, I do not like repeating the same words in both .h and .m file. Note, that in the following example the line is almost identical in both files:

// file.h
extern NSString* const MyConst;

//file.m
NSString* const MyConst = @"Lorem ipsum";

Therefore, what I like to do is to use some C preprocessor machinery. Let me explain through the example.

I have a header file which defines the macro STR_CONST(name, value):

// StringConsts.h
#ifdef SYNTHESIZE_CONSTS
# define STR_CONST(name, value) NSString* const name = @ value
#else
# define STR_CONST(name, value) extern NSString* const name
#endif

The in my .h/.m pair where I want to define the constant I do the following:

// myfile.h
#import 

STR_CONST(MyConst, "Lorem Ipsum");
STR_CONST(MyOtherConst, "Hello world");

// myfile.m
#define SYNTHESIZE_CONSTS
#import "myfile.h"

et voila, I have all the information about the constants in .h file only.