NSString no 'assign', 'retain', or 'copy' attribute is specified

Question

I\'m declaring an NSString property in a class and objective-c is complaining that:

NSString no \'assign\', \'retain\', or \'copy\' attribute is specifie

Answer 1

Cocoa uses reference counting to manage memory. Objects with a reference count of 0 are deleted.

• assign - does nothing to reference count simply points your variable to the data
• retain - points your variable to data and adds 1 to reference count, data is guaranteed to be there while your variable is still alive
• copy - makes a copy of data, points your variable at it and makes the retain count 1

More detail here, at Apple's own documentation.