Public static variable in iOS

Question

public class CommandType {
    public static final int DELETE = -1;
}

//Class B - Access from class B here
CommandType.DELETE

If i am using

//ClassA.h
extern int  const kMyConstant;

//ClassA.m
int  const kMyConstant = @"my constant"; 

switch (messagetype) {
                case kMyConstant: //Can't set const value here
    }

I need to convert this to objectiveC. Is it possible to do?

This question has been asked before: http://stackoverflow.com/questions/6188672/where-do-you-declare-constant-in-objective-c, http://stackoverflow.com/questions/554256/integer-constants, ... — David Silverfarmer, Jan 21 '15 at 10:58
in switch statement you CAN'T use NSString. In switch you should use int or char. In order to do this you can use ENUM — Сергей Олейнич, Jan 21 '15 at 12:28
Oh, I hate downvotes without comments! :( If you are so clever why didn't you answer the question ?? – — SampathKumar, Jan 23 '15 at 14:35

Сергей Олейнич · Answer 1 · 2015-01-21T12:58:45.517

Try this in your .m file if you want to use this in your class.

#import "yourimport";
static const NSInteger DELETE = -1;
@implementation YourClass

If you want that it would be global variable you should do this in.h file

extern NSInteger *const DELETE;

In order to do this

//ClassA.h
extern int  const kMyConstant;

//ClassA.m
int  const kMyConstant = @"my constant"; 

switch (messagetype) {
                case kMyConstant: //Can't set const value here
    }

You should create ENUM in .h:

#import <AVFoundation/AVFoundation.h> 
typedef NS_ENUM(NSInteger, YourType) {
    YourTypeConstant1                      = 0,
    YourTypeConstant2,
};

@interface YourViewController : ViewController

And then:

NSNumber *number = @(YourTypeConstant1);
switch (number) {

        case YourTypeConstant1:

            //your code
            break;

        case YourTypeConstant1:

           //your code
           break;
default:
//your default code
break;}

If you mark it as `extern` in .h file, you must remove `static` in .m file, otherwise it won't compile. — Michał Ciuba, Jan 21 '15 at 10:58

score 1 · Answer 2 · answered Jan 21 '15 at 10:49

The best way to handle a integer constant is to declare it in a .h file:

static const NSInteger DELETE = -1;

Then every file (in your case e.g. Class B) that imports the .h file will be able to access the constant e.g.:

NSInteger test = DELETE;

That is the closest you will get to the java code...

Public static variable in iOS

2 Answers2