Explanation of Cocoa @selector usage

Question

I\'m new to Cocoa/Cocoa Touch, and working through a development book. I\'ve come across situations where the @selector() operator is used. I\'m a bit lost on how and when the

Answer 1

The selector operator provides a way to refer to a method provided by an object, somewhat similar to a function pointer in C. It is useful because it allows you to decouple the process of calling methods on an object. For example one piece of code could provide a method, and another piece of code could apply that method to a given set of objects.

Examples:

Test to see if an object implements a certain method:

[object respondsToSelector:@selector(methodName)]

Store a method to later call on an object;

SEL method = @selector(methodName);
[object performSelector:method];

Call a method on a different thread (useful for GUI work).

[object performSelectorOnMainThread:@selector(methodName)]