The Open Closed Principle

The open closed principle means that code or a module should be closed for modification, but open for extension. To the extent that which you can do that, what this principle is saying - and I'm not saying it's always true - then you have produced a better design. You know, design A is better than design B, because it is easier to extend, and you don't have to modify. Yeah. So we've covered the S of solid, and I think we've done at least some justice to Dan's point about it,. meaning many things to many people. And so maybe we should move on to the O, which, again, I've already forgotten what O is.