NSString to enum Value (Objc)

Question

typedef enum {
    red = 10,
    blue = 21,
    white = 32
} colors;
#define ENUMvalue2str(value)   @(#value)

I used ENUMvalue2str(white) get @"white"， now, I want get white from @"white". not use NSArray, how to do it ?

`I want get white from @"white"` <- this is not clear to me what you want to achieve. — Cœur, Jun 02 '17 at 08:19
You may have answers on https://stackoverflow.com/questions/925991/objective-c-nsstring-to-enum or https://stackoverflow.com/questions/7083361/objective-c-convert-string-to-enum or https://stackoverflow.com/questions/16844728/converting-from-string-to-enum-in-c — Cœur, Jun 02 '17 at 08:26

score 0 · Accepted Answer · answered Jun 02 '17 at 13:46

enums are from pure C. There is no runtime information about the label strings. Therefore it is impossible to translate an instance of an NSString into a value of an enumeration label. The only way to do that is to have if cascades.

This is one reason, why I do not use C enumerations, if it is possible. I simply define strings for the label and pass the string itself as argument, if the enum value is simply a marker, an option. If I need a combination of values (aka bit sets) I use instances of NSSet with strings.

If your are interested in a specific value of an enumeration (instead of having simply 0, 1, 2, …), you can use dictionaries as explained in the link in the comment to your Q.

NSString to enum Value (Objc)

1 Answers1