CODEWITHSUNDEEP
iosobjective-cmemory-management
elp
elp

Reputation: 8131

Why this RELEASE don't produce RUNTIME ERROR?

This my snippet:

  Foo *myFooOne = [[Foo alloc] initWithName:@"my string"];
  Foo *myFooTwo = myFooOne;

  [myFooOne release];

  NSLog(@"Name: %@", myFooTwo.name);

why myFooTwo.name produce correctly output, instead of a runtime error ?

2011-10-28 14:45:10.718 Example[6410:f803] Name: my string

thanks.

Upvotes: 1

Views: 82

Answers (2)

Pedro Mancheno
Pedro Mancheno

Reputation: 5237

When you release the Foo object, it's previously allocated memory is freed, but that does not necessarily mean that the data in that memory block is 'cleared'. In this case the myFooTwo pointer is still pointing at valid Foo data.

This could not always be the case.

Upvotes: 1

Codo
Codo

Reputation: 78845

You are just lucky that the released memory hasn't been reused for something else and been overwritten. Otherwise, it would fail.

Run you app with NSZombieEnabled set to YES and it should raise an error at run-time.

Upvotes: 4

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