By changing the .h file
Quote:
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from "NSMutableArray *countries" which was inside of the @interface...@end block to "extern NSMutableArray *countries;" which is now outside of the @interface...@end block
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you are saying that
countries, which used to be an instance variable of the class, is now a global variable. So
countries is what you want to use instead of
globalArray.
Next, you should not use "extern" in the .m file. "extern" is only for the declaration in the .h file, not for the actual variable definition in the .m file.
Finally, you already created
countries and it is retained (because you used
alloc and did not release it).
So if you take away that one unnecessary
extern, then you would have the setup you need to make
countries a global NSMutableArray. To access it in other views, only need to import the .h file that declares
countries into the .m file of those views.
I should warn you that using a global variable like this invites problems if you are careless. Remember that
countries is not actually the NSMutableArray itself. It is just a pointer to that NSMutableArray. Like all Objective-C objects, this object can only be accessed through pointers. And the memory that it points to needs to be dynamically managed. Normally this dynamic memory management is taken care of for you when you make a property of an object.
By looking at your code, I see that you set
countries in response to a didSelectRowAtIndexPath. Therefore you might set
countries more than once. When you do that, the old NSMutableArray that
countries used to point to becomes leaked memory, unless you first release it. This would have been handled automatically for you if you were content to use properties and the standard retaining setter that comes with it. But by implementing a global variable, you have abandoned the use of properties. So you have to do the work that the properties would have done for you automatically. If you really understand the retain/release system and are committed to taking the care needed to release dynamically allocated memory at just the right time, then you can make this work. But this is not normally done.
OK, I have done my best to warn you against using a global variable as a pointer to a NSMutableArray. So the choice is up to you.
