Question

I was wondering if I can directly alloc, init an ivar now with ARC (Because if I remember well it wasn’t possible without ARC because it would leak memory no) ?

Example (consider an ivar declared like this) :

@property (nonatomic, strong) NSArray *myArray;

@synthetize myArray = _myArray;

And then do

self.myArray = [[NSArray alloc] initWithObjects:object1, object2, nil]; //I know I could directly use [NSArray arrayWithObjects:...] but that's the purpose of my question 

Answer 1

Yes.

The only difference between using alloc/initWithObjects: and arrayWithObjects: is that the former leaves you with a retained object, while the second doesn’t. If for some reason you wanted to use the former to initialize a property, you’d want to add a call to autorelease to avoid a leak. So you’d do this:

self.myArray = [[[NSArray alloc] initWithObjects:foo, bar, nil] autorelease];

You’re correct that with ARC, the compiler will take care of adding that for you, so you can now just say:

self.myArray = [[NSArray alloc] initWithObjects:foo, bar, nil];