Question

I have a property defined like this:

@property (nonatomic, retain) MyClass *someObject;

I’m currently using this assignment statement:

someObject = [[MyClass alloc] init];

In terms of memory managment is the above assignment statement equivalent to:

self.someObject = [[[MyClass alloc] init] autorelease];

Assume @synthesize someObject; is in the @implementation section. Also I’m not using ARC.

Answer 1

Note: The following is based on the EDITED version of the original post, where “assign” has been replaced with “retain” —

Yes, the two are “equivalent”, in that they will both result in leaving the MyClass object (properly) retained with a retain count of 1 in the property. The second version goes through some extra work, which may or may not be an issue, depending on how performance-sensitive you are.

Some people argue you should never use the property reference (ie, self.propname) from within the class, but instead reference the instance variable, especially for initialization and deallocation. Others argue just the opposite. I generally favor always using the property reference, except during initialization where (as in this case) using it might result in an extraneous retain/autorelease.