retain recursively applied to objects?

FROM : Todd Heberlein
DATE : Sun Apr 29 02:58:59 2007

My questions are: (1) When an NSArray object is sent a "retain" 
message, is that message also sent to all the objects it contains? 
(2) When a subclass of an NSObject receives a "retain" message, does 
it forward the message to each instance variable in the object?

As example, suppose there is an EvilCorp, which has an array of 
showrooms, each showroom has an array of cars, and each car has an 
array of parts.  When I send the "retain" message to the first array 
of showrooms, will that "retain" message be propagated all the way 
down to the car's parts objects?  (pseudo code below is provided just 
for illustration purposes).

Thanks,

Todd



@interface EvilCorp : NSObject
{
   NSString * boss;
   NSMutableArray * showrooms;  // a list of showrooms
}
...
@ end



@interface Showroom : NSObject
{
   NSString * name;
   NSMutableArray * carList;    // list of cars
}
...
@end



@interface Cars : NSObject
{
   int    id_number;
   NSMutableArray * partsList;    // list of parts
}
...
@end