Obj-C, how do I release a NSString return value?

I'm trying to gain a NSString value from my database in a function, ho开发者_运维百科wever I keep get analyzer warnings. Heres my code...

- (NSString*)getCategoryDesc:(int)pintCid { 
NSString *ret;
ret = value from my db ...  
return [ret autorelease];
}

It doesn't like

return ret;
return [ret retain];

The key point (which you're not showing us) is: what does "value from my db" do?

If it's doing something like:

ret = [[NSString alloc] initWithString:@"something"];

then you are responsible for releasing the object, but if it's doing something like

ret = [NSString stringWithString:@"something"];

you do not need to release it (and, indeed, you must NOT).

Because your method is named "get*" (and not "create*"), you need to return an object that the caller does not own (generally, that means an autoreleased object).

Read up on the object ownership policy rules.