How to keep single object with ARC mode?

Question

I want to keep one single object in application, and do not release.

@implementation MyClass

    static MyClass *sharedInstance = nil;
    + (MyClass *)sharedInstance {
        if (!sharedInstance) {
            sharedInstance = [[super alloc] init];
        }
        return sharedInstance;
    }
@end

I can get single object by [MyClass sharedInstance], it works well in Non-ARC mode.

But the object will release when change to ARC mode.

The code you have written here is correct, if not threadsafe. If the object is getting deallocated, the problem is elsewhere. — Chuck, Mar 07 '13 at 07:20
Why are you calling `[super alloc]`? It should be `[self alloc]` or `[MyClass alloc]`. Also, why is `sharedInstance` static variable of type `MyClass` and the return type of the `sharedInstance` class method `Ap`? They need to be the same. — rmaddy, Mar 07 '13 at 07:34
See http://stackoverflow.com/questions/5720029/create-singleton-using-gcds-dispatch-once-in-objective-c for a better way to create a singleton. — rmaddy, Mar 07 '13 at 07:37

nneonneo · Accepted Answer · 2013-03-07T07:47:06.657

3

Why do you think it would release? You've assigned it to a static variable tracked by ARC.

edited Mar 07 '13 at 07:47

answered Mar 07 '13 at 07:20

nneonneo

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The reason is not that the variable is declared `static`, but that its storage duration is static, same as all file scope variables. In this context `static` only means internal linkage. – Nikolai Ruhe Mar 07 '13 at 07:45

How to keep single object with ARC mode?

1 Answers1