How to know if object needs release

Have you read the Apple guide to memory management? It covers this in great detail. If not, I suggest you do then come back if you then have any questions or need anything clarifying.

I could summarise the memory management rules for you (they aren't that complicated) but you'd learn more from the Apple docs.

 

Im not sure what that code you posted says or does, but it's not "Init" that means you need to release it's "alloc".

Yes sometimes alloc is followed by init, but alloc is the main concern.

Alloc means you're allocating memory for the object. Release means you give it back. Init just initializes an already allocated object.

For example:

NSNumber *number = [[NSNumber alloc] initWithInt:4]; That needs to be released.

This:

number = [NSNumber numberWithInt:4]; this does not need to be released.

 

What exactly wasn't clear to you from the documentation? Ask a specific question and I will try and help.

 

Well that depends entirely on the context. Did you alloc the controller instance, or retain it somewhere? If so, then yes. A small snippet of code out of context isn't really much to go on.

 

I'm assuming the code isn't taken directly from your app as the first line isn't syntatically correct. Assuming it should be [NSArray arrayWithArray:] then the answer is no, as this method neither does not start with alloc, new or copy. In this case you can assume the method returns an autoreleased object so unless you explicitly retain it, then you do not need to release it.