... is a sequence of characters, usually human- readable, so you can probably guess (correctly) that an NSString is a sequence of characters in Cocoa. Learn Objective- C on the Mac Penciled by ... the user interface, such as data structures and communication mechanisms. All the programs in this book are based on the Foundation framework. Learn Objective- C on the Mac Copyright © 2009 ... like C, Objective- C uses header files to hold the declarations of elements such as structs, symbolic constants, and function prototypes. In C, you use the #include statement to inform the compiler...