Object-Oriented Programming

Abstract

The traditional view of software systems is that they consist of the data that represents some information and a set of procedures that manipulates the data. However, this doesn’t always work... For instance, if you are given the instruction

$$subtract\;38\;from\;16$$

, then the answer will depend on the context. If the 16 represents your bank balance, what happens depends on your bank manager. If he won’t give you an overdraft, the result remains 16 but you don’t get the 38. If the 16 is degrees Celsius, then the answer is -22. If you’re playing darts, the answer is 16, and you’ve lost the rest of your turn.

‘Be what you seem to be’—or, if you’d like it put more simply—‘Never imagine yourself not to be otherwise than what it might appear to others that what you were or might have been was not otherwise than what you had been would have appeared to them to be otherwise.’

Alice’s Adventures in Wonderland