Integer constants

Question

If I declare a string constant like so:

You should create a header file like

// Constants.h
extern NSString * const MyFirstConstant;
extern NSString * const MySecondConstant;
//etc.

You can include this file in each file that uses the constants or in the pre-compiled header for the project.

You define these constants in a .m file like

// Constants.m

NSString * const MyFirstConstant = @"FirstConstant";
NSString * const MySecondConstant = @"SecondConstant";

What do I do to define integer constants?

Answer 1

Replace NSString* with NSInteger.

This is true of any constant type, be it a primitive such as int/float, or a class such as NSString or NSInteger.

The only thing to be aware of is whether you desire a constant or a pointer to a constant (such as withNSString), and how it's initialized in the .m file

Integer example:

// constants.h
extern NSInteger const MyIntegerConstant;

// constants.m
NSInteger const MyIntegerConstant = 666;

(Note: for the reason why NSInteger instead of just regular "int", see this post)

Class example:

// constants.h
extern MyClass* const MyClassConstant;

// constants.m
MyClass* const MyClassConstant= [[MyClass alloc] initWith: paramOne and:paramTwo];