copy and mutableCopy of NSMutableString

For NSMutableString AND NSString

say we have:

1	NSMutableString * temp = [[NSMutableString alloc] initWithFormat:@"hahaha"];

If you use

1	NSArray * copyArray = [temp copy]

it will return you an immutable object (NSString*) with its own address. This means you cannot change the data.
Hence, even if you declare a NSMutableString pointer, and use setString to change the data, the compiler will give you an exception.

NSString * shallowCopy = [temp copy];

//or

NSMutableString * shallowCopy = [temp copy];

if you use [temp mutableCopy], it will return an mutable object (NSMutableString*) with its own address.
However, be sure that you declare a NSMutableString * so that you can use setString to change the data and see the difference.

NSMutableString * temp = [[NSMutableString alloc] initWithFormat:@"hahaha"];

NSLog(@"address of temp: %p", &temp);

NSMutableString * shallowCopy = [temp copy]; //returns immutable object, has own address, same data

NSLog(@"address of shallowCopy: %p", &shallowCopy);

NSMutableString * mutableCopy = [temp mutableCopy]; //returns mutable (changeable) object, own address

NSLog(@"address of mutableCopy: %p", &mutableCopy);