S.O.L.I.D. object oriented design principles

Learn about the SOLID principles of object oriented design.

Open presentation slides

Focus of this lesson

This lesson will focus on writing code that touches upon the various aspects of the SOLID principles.

What you need

• IntelliJ Community Edition: IntelliJ Community Edition
• JDK Development Kit (JDK 17 or later): Java SE Development Kit
• Alternative dev kit (Java 17 or later): Eclipse Temurin Java Development Kit

Prerequisites

• Some previous experience with any object-oriented programming language is helpful

How to get started

• Start by cloning this repository into a folder on your computer. If you've never used git before, you can alternatively use the the "Download ZIP" button to the right.
• Although you have this README.md file on your computer it's easier to read it on GitHub, so we recommend you keep this page open with the exercise tasks.

Exercises

This repository contains a set of exercises organized in markdown files. Each exercise builds on the previous.

• Exercise 1 - Introduction (Start here)
• Exercise 2 - Dependency Inversion Principle
• Exercise 3 - Single Responsibility Principle
• Exercise 4 - Interface Segregation Principle

Tip: The markdown files are best viewed on GitHub rather than on your computer.

Have fun! And remember to ask an instructor if you're stuck.

Helpful resources

• SOLID (object-oriented design) on Wikipedia
• IntelliJ documentation

Symbols and notation used in exercises

Icons with special meaning

• ✏️ - A task you should do
• 📖 - A section of text to read (no tasks, just information).
• 💡 - Additional information.
• ❗ - Something important.
• ❓ - Open-ended question for the reader ("What do you think would happen if...")
• 💩 - Bad practice (don't-do-this)
• ⭐ - A bonus task (not required)

Keyboard keys

Will look like this:

CTRL + ALT + C

Diff blocks

Emphasizes how lines of text should change.

- this text was removed
+ and replaced with this text