In iOS how to use NS_ENUM?

Question

I know that such questions are asked before. I looked on the net find examples but I can not figure out how to use NS_ENUM in my code. I have a list of error codes. To manage them I want to use NS_ENUM. I create a class which contains all my public const for the application. I want to define my enum here and use it everywhere in the app.

My code in .h file:

typedef NS_ENUM(NSInteger, wsErrEnum); 

In my .m file:

typedef NS_ENUM(NSInteger, wsErrEnum) {
    ERR_NONE = 0,
    ERR_HOST_TIMEOUT = 1
};

I thought that I can check in the following manner:

if(result.ErrCode == wsErrEnum.ERR_NONE) {
// do stuff ...
}

, but ERR_NONE is not visible as property.

So my question is how to define and use NS_ENUM in this case.

EDIT:

Using

if(result.ErrCode == ERR_NONE) {
            NSLog(@"It is OK!");
        }

give me error that ERR_NONE is undefined.

EDIT 2:

I understand the problem. I declare NS_ENUM in my .h file (as some comments and answers suggest) and the error disappears. I try this before but in that case I did not use enum properly - I use is as wsErrEnum.ERR_NONE. 10x for help.

P.S. My class is #imported in the .m file where I try to make this comparison.

Answer 1

The only problem here is that you've declared the enum's values in your .m file.

You should declare the entire enum (values included) in your .h file. By declaring the enum type wsErrNum in your .h file and the values in your .m file, you've hidden the values from all other classes.

So, in your .h file:

typedef NS_ENUM(NSInteger, wsErrEnum) {
    ERR_NONE = 0,
    ERR_HOST_TIMEOUT = 1
};

Nothing needs to go in your .m file to declare this enum.

Answer 2

In Swift :

if result.ErrCode == wsErrEnum.ERR_NONE {
   // do stuff ...
}

In Objective-C :

if(result.ErrCode == ERR_NONE) {
   // do stuff ...
}

The real issue is that you have split up the declaration of wsErrEnum, remove it from the .m file and place the full delcaration in the .h:

typedef NS_ENUM(NSInteger, wsErrEnum) {
    ERR_NONE = 0,
    ERR_HOST_TIMEOUT = 1
};

But better is something like:

typedef NS_ENUM(NSInteger, wsErrEnum) {
    wsErrEnumName = 0,
    wsErrEnumTimeOut = 1
};

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Just a small remark, properties like your ErrCode should not started with a capital letter.