Objective-C has the message-passing approach to object-oriented programming; all dispatch was at run-time, and an object could delegate any unrecognized message

Objective-C has the message-passing approach to object-oriented programming; all dispatch was at run-time, and an object could delegate any unrecognized messages or decide for itself how to respond to them. I suppose it's not "modern" anymore though - and it doesn't look like swift kept this paradigm.