Question

I want a NSMutableArray global. I have the following setup:

code.h
extern NSMutableArray *global
@interface
@end

code.m
NSMutableArray *global=nil;
@implementation
...
global=variable_mutablearray; //copy variable_mutablearray to global
@end

I’m pretty sure that what I’m doing setting an existing nsmutablearray to the global variable is not correct. What should I be doing?

Answer 1

Globals are not the best thing to use in Objective C: it is much better to use a singleton.

You can do it like this:

Header:

@interface Globals : NSObject
+(NSMutableArray*)array;
@end

Implementation:

@implementation Globals
+(NSMutableArray*)array {
    static NSMutableArray *statArray;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        statArray = [NSMutableArray array];
    });
    return statArray;
}
@end

Usage:

NSMutableArray *ga = [Globals array];