Intro

Even before Swift was released, iOS / Cocoa developers could use third party frameworks like ObjectiveSugar or ReactiveCocoa in order to gain functional programming constructs like map, flatMap or filter.

With Swift, they have become first class language citizens. There are many advantages to using them over a standard for loop. They typically express your intent better, they require less code, and they can be chained together in order to build up complex logic in a clear way.

In this post, I'd like to show another very cool functional addition to Swift which can sometimes be a better solution than map / filter constructs: reduce.