https://en.wikipedia.org/wiki/Object-Oriented_Software_Construction https://en.wikipedia.org/wiki/Object-Oriented_Software_Const... Although http://touch.ethz.

https://en.wikipedia.org/wiki/Object-Oriented_Software_Construction https://en.wikipedia.org/wiki/Object-Oriented_Software_Const... Although http://touch.ethz.ch/ http://touch.ethz.ch/ looks like an update to the classic. The main take away, which is really really really important is Design by Contract.