Re: An Array of structs

On Nov 27, 2009, at 12:35, John Love wrote:

> In my .h file, I have:
> 
> typedef struct YearAmt {
> 	NSString  *year;
> 	int       amount;
> } YearAmt;
> 
> extern NSString *testy;
> extern YearAmt gTest[];
> 
> In the corresponding .m file:
> 
> NSString *testy = @"testy";
> YearAmt gTest[] = {{testy, 10}  /*, + others */};
> 
> I get "Initializer element is not constant. This pertains to the NSString* because if I directly substitute the following, no compile error happens:
> YearAmt gTest[] = {{@"testy", 10}
> 
> What fundamental pertaining to C or C++ am I not getting?
> 
> 
> John Love
> Touch the Future! Teach!

Well, the error says it all: you can only use constants to initialize a global variable. testy is a variable, not a constant, while @"testy" is a constant. If you want to initialize a global variable using a non-constant  variable, you should do that in an initializer like +initialize or +load.

Christiaan