Are side-effects possible in pure functional programming

Question

I have been trying to wrap my head around functional programming for a while now? I have looked up lambda calculus, LISP, OCML, F# and even combinatorial logic but the main

Answer 1

Functional Programming is about limiting & isolating side-effects, not trying to get entirely rid of them... because you can't.

... and yes I find FP useful (certainly with Erlang anyways): I find it is easier to get from "idea" to "program" (or problem to solution ;)... but of course that could just be me.