Question

I’ve people who use [variable release] and some other times variable = nil to clean up memory?

When do you use each one? and what are the differences?

Answer 1

If a property is set to retain, then these 3 are equivalent:

1. [self setProperty:nil];
2. self.property = nil;
3. [property release]; property = nil;

In each case, the object will be released, and then set to nil so that all access to the object from then on will not be allowed. “nilling” the instance variable is handy since it ensures you can only ever release the object once in this context because calling self.property = nil twice will do nothing the second time, but calling [property release] will release the object twice even though you likely only retain it once.

Most of the time I find it least bug prone to let retain properties do their thing and try to stay away from explicit retain and release calls most of the time.