Obj-C中适当的常量

Question

I seem to be having difficulty understanding how to use Class static consts in Objective-C.

I come form a PHP background, and really what im trying to do is the equivalent of this:

MyObject.php

<?
class MyObject {

    const A_VALUE = 1;
    const ANOTHER_VALUE = 2;

}
?>

Which can be used like

MyObject::A_VALUE

and inside the class like

self::A_VALUE

I want to kind of replicate this behaviour in Obj-C, but I understand theres a FAR different syntax.

in Objective-C

I figured it would look something similar to this

MyObject.h

static int A_VALUE = 1;
static int ANOTHER_VALUE = 2;

@interface MyObject : NSObject;

This TECHNICALLY works, but it throws a GREAT deal of Warnings about unused variables

HOWEVER

MyObject.h

static NSString *A_VALUE = @"1";
static NSString *ANOTHER_VALUE = @"2";

@interface MyObject : NSObject;

THIS works without error. Despite not being used anywhere.

Well, I dont want to use a large series of strings, not only does this not feel very efficient at all (especially when theres many), but I hate looking at my code nd seeing a bunch of

if( [value isEqualToString:A_VALUE] ) {

Just. Gross. Could be worse, but eww. I would prefer:

if( value == A_VALUE ) {

However what i have works for right now, but ive been at a bit of a loss.

What is the proper way in Objective C to make consts (specifically int)

Cheers everyone!

Answer 1

You should define your integer constant this way:

static const NSInteger kYourConstString = 4;

and for your string:

static NSString *const kYourConstString = @"An example";

in your .m file. The static keyword will make the variable scope local to the compilation unit: your .m file.

Answer 2

或将enum用于int ，将#define用于字符串。