Am reading the book "Objective-C Programming" by Big Nerd Ranch, and am not sure about the differentiation.
Context: NSLog() is an Objective-C function (not a method!) that works a lot like printf(). In NSLog(), however, the format string is actually an instance of NSString.
A method is just a function that is defined as part of a class. A plain function, such as NSLog or printf, does not belong to a class.
There is no such thing as an "Objective-C function." NSLog is a function, same as any other standard function in the library, it just happens to take an Objective-C object, but those are just pointers so they can interact with C code just fine. There is nothing 'special' about NSLog.
A method on the other hand is part of an Objective-C class.
Methods belong to classes & objects, and are invoked via message passing. Functions are not attached to a specific class or object, and work exactly as they do in C.
A function in Obj-C is not scoped to a specific class, whereas a method is scoped to a class.
