Question

Possible Duplicate:
Class methods which create new instances

I am wondering how to emulate the instantiation of classes like NSString, NSArray and such like this: [NSArray arrayWithObject:object]… in hope of eliminating inits and allocs.

I may not be familiar with what that actually does. According the the Documentation, [NSSArray array] creates and returns an empty array. What does that really mean, any allocations?

I want to be able to have a custom NSObject class and do: [CustomObj customObjWithData:data]

Thanks!

Answer 1

First write a corresponding custom init... method:

- (id)initWithFoo:(Foo *)aFoo
{
     // Do init stuff.
}

Then add a custom factory method that calls alloc and your custom init... method:

+ (id)customObjWithFoo:(Foo *)aFoo
{
    return [[[self alloc] initWithFoo:aFoo] autorelease];
}

If compiling with ARC, omit the autorelease call.