Where OOP shines is implementing user interfaces. Most engineers doing math can ignore objects. But when a programmer has to implement a partitionable window with scroll bars and menus, constructing complicated objects built of simpler objects is a mess without OOP.

Get your dad a copy of the classic Scientific and Engineering C++: An Introduction With Advanced Techniques and Examples by John Barton and Lee Nackman. It was written to introduce C++ to Fortran programmers using examples from scientific/mathematical domains. The fact that it is old (from 1994) makes it better suited for folks from Fortran (or other languages) since there is none of the complexity of "Modern C++" to confuse them. Check reviews on Amazon etc.

I guess as a typical engineer (not CS person type of engineer or software engineer) it is easy to think that. One might be working with machines or buildings and so on, all which require _calculation_ of processes. Those are typical cases for "just write a correct function", possibly one that takes many things into account. For such scenario OOP is truly useless and only over-complicates the matter. However, when we get to simulations, where maybe there is no known formula, or the precise calculation would be too expensive, then OOP can make sense. Doesn't have to, but could.

Seems like a common theme of every veteran to dress the way used to in their prime for the rest of their lives, listen to the same music, watch the same movies, etc. and to use the same belief systems as well. On the one hand, if it worked for them, why not? There's no incentive to change. Heck, it is very much the definition of conservatism. Old men who don't change is so common that it borders on proverbial.

Very rarely, however, do you see a brilliant mind like Richard Feynman, a man who was so open to new ideas and out of the box thinking. Even in old age. Seeing someone, in good faith, question what they believe in light of new knowledge is very rare. Now that is a special thing.

Chad Dad

Fortran has OO features these days. It is nice.

I am kind of dumb and old-school so I wrote a bunch of code using macros to handle multiple precisions. If I could go back in time, I’d definitely just use object oriented code. In either case, though, “we can try a mixed precision implementation, I automatically generated single precision” is an incredibly liberating thing to be able to say as a computational scientist!