SOLID is one of the most popular sets of design principles in object-oriented software development. It’s a mnemonic acronym for the following five design principles:

• Single Responsibility Principle

• Open/Closed Principle

• Liskov Substitution Principle

• Interface Segregation Principle

• Dependency Inversion Principle

This is a Swift Playground that has code snippets which show how applying SOLID principles effects code design.

For each principle, there are two files in Sources folder;

• Before.swift files: A default implementation of sample case

• After.swift files: Related Principle applied version of the case

to show the difference in simple and clear way.