Objective C: Memory Management, releasing an object with multiple references - objective-c

Question

I would like to release a Car object present in the dealer. I would like to know what is the right way of doing it. NSMutableArray Inventory stores the cars for a particular dealer. So, now I would like to present the user with a delete functionality, so, user could select the car using the Vin Number and delete it. But if I try to find the car and release the reference that doesn't works. Would I need to remove the object from the Array and then, release the reference? I am fairly new to objective c and in the initial learning phase. Thank you.
#import "Dealer.h"
#import "Address.h"
#import "PhoneNumber.h"
#implementation Dealer
static NSInteger dealerIdAllocater = 0;
-(id) init{
self = [super init];
self.dealerId = ++dealerIdAllocater;
self.addressList = [[NSMutableArray alloc] init];
self.inventory = [[NSMutableArray alloc] init];
return self;
}
#synthesize dealerId, name, addressList, inventory;
-(void)addCarInInventory:(Car*)car{
[self.inventory addObject: car];
}
-(void)displayAddresses{
for(Address *address in self.addressList){
NSLog(#"Street Address: %#", address.streetAddress);
NSLog(#"City: %#", address.city);
NSLog(#"State: %#", address.state);
NSLog(#"Country: %#", address.country);
for(int i=0; i<[address.phoneNumber count]; i++){
PhoneNumber *phoneNumber = [address.phoneNumber objectAtIndex:i];
NSLog(#"Phone Number %i, %#", i, phoneNumber.phoneNumber);
}
NSLog(#"--------------");
}
}
-(void)displayInventory{
for(Car *car in self.inventory){
[car displayInformation];
}
NSLog(#"--------------");
}
-(Car *)findCarById:(NSString *)vinNumber{
for(Car *car in self.inventory){
if ([vinNumber isEqualToString:car.vinNumber]) {
return car;
}
}
return nil;
}
#end

Answer 1

Would I need to remove the object from the Array and then, release the reference?
Yes, containers such as NSMutableArrays increment the retain count of objects by 1 when added to them. This is to make sure the container will always hold a valid reference to an object. When you remove an object from the container, the retain count will be decremented by 1.