I don't understand the couple other posters who are dismissing this article. it is exactly what it claims to be, a practical introduction to functional programming. I'd also like to echo poster vvanders sentiments about Rust and how it compliments the functional style. I've experienced the same feelings, although I did it while working in Swift. And for those out there asking "why is FP better", I submit that it allows for fewer ways for me to shoot myself in the foot.