use #define in objective C and access in swift class

Question

I have define #define baseUrl [NSString stringWithFormat:@"%@api/v4", MAINURL] in objective c class and can access anywhere in project. But now i have created swift file in exiting objective c project and want to access baseurl in swift but error received.

Use of unresolved identifier 'baseUrl'

how can resolve it?

Answer 1

Importing Objective-C macros into Swift doesn't always work. According to documentation:

Swift automatically imports simple, constant-like macros, declared with the #define directive, as global constants. Macros are imported when they use literals for string, floating-point, or integer values, or use operators like +, -, >, and == between literals or previously defined macros.

C macros that are more complex than simple constant definitions have no counterpart in Swift.

An alternative in your case would be to use a function that returns the value defined by macro

// .h file
#define baseUrl [NSString stringWithFormat:@"%@api/v4", MAINURL]
+ (NSString*) BaseUrl;

// .m file
+ (NSString*) BaseUrl { return baseUrl }