On their own, variables can’t do much more than keep track of their assigned values. While this is vital, they are not very useful on their own in terms of creating meaningful applications. So, how do we go about creating actions and driving behavior in our code? The short answer is by using methods.

Before we get to what methods are and how to use them, we should clarify a small point of terminology. In the world of programming, you’ll commonly see the terms method and function used interchangeably, especially in regard to Unity.

Since C# is an object-oriented language (this is something that we’ll cover in Chapter 5, Working with Classes, Structs, and OOP), we’ll be using the term method for the rest of the book to conform to standard C# guidelines.

When you come across the word function in the Scripting Reference or any other documentation, think method.

Methods drive actions

Like variables, defining programming...

We’ve seen how variables store information and how methods perform actions, but our programming toolkit is still somewhat limited. We need a way of creating a sort of super container, containing variables and methods that can be referenced from within the container itself. Enter classes:

• Conceptually, a class holds related information, actions, and behaviors inside a single container. They can even communicate with each other.
• Technically, classes are data structures. They can contain variables, methods, and other programmatic information, all of which can be referenced when an object of the class is created.
• Practically, a class is a blueprint. It sets out the rules and regulations for any object (called an instance) created using the class blueprint.

You’ve probably realized that classes surround us not only in Unity but in the real world as well. Next, we’ll take a look at the most common Unity class and how...

You might have noticed that LearningCurve has an odd line of text (10 in Figure 2.6) starting with two forward slashes, which were created by default with the script.

These are code comments! In C#, there are a few ways that you can use to create comments, and Visual Studio (and other code editing applications) will often make it even easier with built-in shortcuts.

Some professionals wouldn’t call commenting an essential building block of programming, but I’ll have to respectfully disagree. Correctly commenting out your code with meaningful information is one of the most fundamental habits a new programmer can develop.

Single-line comments

The following single-line comment is like the one we’ve included in LearningCurve:

// This is a single-line comment

Visual Studio doesn’t compile lines starting with two forward slashes (without empty space) as code, so you can use them as much as needed to explain your...

With the building blocks squared away, it’s time to do a little Unity-specific housekeeping before wrapping up this chapter. Specifically, we need to know more about how Unity handles C# scripts attached to GameObjects.

For this example, we’ll keep using our LearningCurve script and Main Camera GameObject.

Scripts become components

All GameObject components are scripts, whether they’re written by you or the good people at Unity. The only difference is that Unity-specific components such as Transform and their respective scripts just aren’t supposed to be edited by users.

The moment a script that you have created is dropped onto a GameObject, it becomes another component of that object, which is why it appears in the Inspector panel. To Unity, it walks, talks, and acts like any other component, complete with public variables underneath the component that can be changed at any time. Even though we aren...

We’ve come a long way in a few short pages, but understanding the overarching theory of fundamental concepts such as variables, methods, and classes will give you a strong foundation to build on. Bear in mind that these building blocks have very real counterparts in the real world. Variables hold values like mailboxes hold letters; methods store instructions like recipes, to be followed for a predefined result; and classes are blueprints just like real blueprints.

You can’t build a house without a well-thought-out design to follow if you expect it to stay standing.

The rest of this book will take you on a deep dive into C# syntax from scratch, starting with more detail in the next chapter on how to create variables, manage value types, and work with simple and complex methods.

1. What is the main purpose of a variable?
2. What role do methods play in scripts?
3. How does a script become a component?
4. What is the purpose of dot notation?

Don’t forget to check your answers against mine in the Pop Quiz Answers appendix to see how you did!

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