How can you do anything useful without mutable state?

Question

I\'ve been reading a lot of stuff about functional programming lately, and I can understand most of it, but the one thing I just can\'t wrap my head around is stateless codi

Answer 1

That's the way FORTRAN would work without COMMON blocks: You'd write methods that had the values you passed in and local variables. That's it.

Object oriented programming brought us state and behavior together, but it was a new idea when I first encountered it from C++ back in 1994.

Geez, I was a functional programmer when I was a mechanical engineer and I didn't know it!