Question

Am I responsible for releasing this string, and is it autorelease by default?

// command is of type NSData*
char cAddress[12];
[command getBytes:cAddress range:NSMakeRange(5,12)];
NSString *someString = [NSString stringWithCharacters:(const unichar*)cAddress length:12];

Answer 1

It’s autoreleased by default.
Retained objects are usually created with methods in the form of:

[[MyClass alloc] ...]
[MyClass new] 
[object copy]