Converting nsstring to macro (#define)

Question

I receive from from the server the following JSON:

{
   .....
   "id":"predifined_id",
   ...
}

In the code I have an int definition for the predifined_id:

#define predifined_id   5

Which means that if I use predifined_id in code it will be translated to int = 5.

How can I fetch this value (5) when I am parsing the JSON?

I have converted the JSON to NSDictionary, but the value that I receive for @"id" key, is NSString

the macros for _compiler time_ only, you cannot deal with them during _runtime_ – they just don't exist in runtime. — holex, Nov 04 '14 at 12:06
@Paulw11, predefined_id will still not be recognised as macro when parsing the JSON. It only be a NSString — Luda, Nov 04 '14 at 12:13
I don't understand what you are trying to do. All #define does is cause the compiler to make a substitution when you compile the program. Do you want to convert the string value from the dictionary to an int? If so, then @mityaika07 is correct — Paulw11, Nov 04 '14 at 12:16
@Paulw11 No, I want to convert the string value from the dictionary to the macro — Luda, Nov 04 '14 at 12:18
You can't convert a string to a macro. A macro is just a compile-time text substitution — Paulw11, Nov 04 '14 at 12:19

score 1 · Answer 1 · answered Nov 04 '14 at 12:04

1

in my code I use this:

NSInteger integerValue = [dict[@"id"] integerValue];

answered Nov 04 '14 at 12:04

mityaika07

score 0 · Answer 2 · answered Nov 04 '14 at 12:05

0

You could simply define it as string

#define predifined_id  @"5"

or convert it later:

[NSString stringWithFormat:@"%d",predefined_id]

answered Nov 04 '14 at 12:05

nicael

2 Answers2