> The other canonical example of OO - "Shapes" - doesn't actually work well at all; It doesn't work better with "plain data", but it exposes the fallacies of tr

> The other canonical example of OO - "Shapes" - doesn't actually work well at all; It doesn't work better with "plain data", but it exposes the fallacies of trying to use OO inheritance to model the real world. Shapes work well, but people do the wrong things with them, as you state... > Every square is a rectangle, so square should inherit from rectangle ... but, you can't stretch width and height independently in a square, so it's not really a rectangle, etc. etc. A square is a just a rectangle where the length and width happen to be the same size and shouldn't be its own class. Books and websites teaching inheritance should stop trying to use it as an example.