Join the Discord: https://discord.gg/4tHeAkxNg7 In this episode I go over 3 core concepts in C/C++: Declaration vs Definition, Header Files, and Linking. Each of these plays a huge role in everyday C++ development, so I think it's worthwhile to explicitly go over what each of these mean, and how to use them when you are coding in C++. Guess a Number Game Solution (Without Headers): https://gist.github.com/codingminecraft/50599773da541765687f185a73a6b438 0:00 In This Episode 0:30 Declaration Vs Definition 3:30 Header Files 6:00 Compiling and Linking Multiple Files 8:49 Linker Errors (Missing External Symbol) 12:19 #pragma once 16:00 Recap 16:20 Challenge 17:02 Guess Number Game Solution --------------------------------------------------------------------- Website: https://ambrosiogabe.github.io/ Github: https://github.com/ambrosiogabe Here are some books I recommend if you want to learn about game engine development more thoroughly. I do not profit off any of these sales, these are just some books that have helped me out :) My Recommended Game Engine Books: Game Engine Architecture: https://www.gameenginebook.com/ Game Physics Cookbook (Read this before the next physics book): https://www.amazon.com/Game-Physics-Cookbook-Gabor-Szauer/dp/1787123669 Game Physics (Ian Millington): https://www.amazon.com/Game-Physics-Engine-Development-Commercial-Grade/dp/0123819768 Game Programming Patterns (Free): https://gameprogrammingpatterns.com/ My Recommended Beginning Game Programming Books: JavaScript Game Design: https://www.apress.com/gp/book/9781430247166 My Recommended Java Books: Data Structures/Algorithms: https://www.amazon.com/Data-Structures-Algorithms-Java-6th-ebook/dp/B00JDRQF8C LWJGL (Free, but I haven't read this thoroughly): https://lwjglgamedev.gitbooks.io/3d-game-development-with-lwjgl/content/