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I'm new to objective C, I'm following "Objective C 5th Edition Stephen Kochan and I don't have anyone to ask my doubts to. I'm confused with this question:
Q. Is it necessary to use "-" or "+" before every property or method declaration in Interface? What will happen if I don't use "-" or "+" before every property or method declaration in Interface?
A "+" before a method indicates a class method. These methods can only operate on class variables (variables common to all objects of a class), and can be called before an object of this class has been instantiated.
A "-" indicates an instance method. These methods can operate on class and instance variables. They are called on an instance of an object.
Yes it is necessary to declare the method type specifier, if you don't declare those method types, you will receive a red warning telling you that you need to specify the method type.
Also it is recommended to assign the method type specifier in order to see which methods are class methods, and which ones are instance methods.
The "-" sign indicates an instance method.
The "+" sign indicates a class method.
