Registers a method with the Objective-C runtime system, maps the method name to a selector, and returns the selector value.
- iOS 2.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
A pointer to a C string. Pass the name of the method you wish to register.
A pointer of type
SEL specifying the selector for the named method.
You must register a method name with the Objective-C runtime system to obtain the method’s selector before you can add the method to a class definition. If the method name has already been registered, this function simply returns the selector.