The original article – Protocol Oriented Programming in Swift: Is it better than Object Oriented Programming? – was published on appcoda.com.
We’re going to talk in-depth about protocol-oriented programming (POP) using Swift 4 in this article. This post is the second and final article in a two part series. If you haven’t read the first, introductory article, please do so before continuing onwards. Today, we’ll: discuss why Swift is considered a “protocol-oriented” language, compare POP and object-oriented programming (OOP), compare value semantics and reference semantics, consider local reasoning, implement delegation with protocols, use protocols as types, use protocol polymorphism, review my real-world POP Swift code, and finally, discuss why I’ve not bought 100% into POP. Download the source code from the article so you can follow along: There are 2 playgrounds and one project on GitHub, both in Xcode 9 format and written in Swift 4.