{"id":855,"date":"2019-12-11T23:26:43","date_gmt":"2019-12-11T23:26:43","guid":{"rendered":"https:\/\/www.danielparente.net\/en\/2019\/12\/11\/methods-in-c-programming-for-unity-game-development-game-development-blog\/"},"modified":"2019-12-11T23:26:43","modified_gmt":"2019-12-11T23:26:43","slug":"methods-in-c-programming-for-unity-game-development-game-development-blog","status":"publish","type":"post","link":"https:\/\/www.danielparente.net\/en\/2019\/12\/11\/methods-in-c-programming-for-unity-game-development-game-development-blog\/","title":{"rendered":"Methods in C# \u2013 Programming for Unity Game Development \u2013 Game Development Blog"},"content":{"rendered":"

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\n<\/p>\n

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\u201cIt is the method behind the madness that makes it madness.\u2019<\/p>\n

\u2015 Marty Rubin<\/cite><\/p><\/blockquote>\n

<\/p>\n

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Do you want to be a game developer? Learn C# programming fundamentals in Unity with this free tutorial by @MammothCompany! All about methods\u2026.Where would we be without them?<\/p>\n

open a new Unity project<\/a><\/strong>.<\/p>\n

\n

Sure, Unity gives us two default methods in each new script we make. But to make a game, we\u2019re going to need a lot more than that. <\/p>\n<\/blockquote>\n

Part 1: What Is A Method? <\/strong><\/h2>\n

A method is a task or function that you can
\nreuse throughout code simply by calling its name. <\/p>\n

But before you can call a method, you must declare it and set it up, including any parameters <\/strong>(data that the method will use to perform its task) or return values<\/strong> (the value that the method will spit out when it has completed its task, usually to determine that value.) <\/p>\n

Making a new method also allows you to
\nreuse it easily by simply calling its name.<\/p>\n

The best way to learn is by doing. So, let\u2019s make a new method for a Unity game.<\/p>\n

Part 2: Making a C# Method<\/h2>\n

Open the script you made that controls your game, typically called GameController.cs. If you don\u2019t have a Game Controller yet, check out our previous tutorial. <\/p>\n

Type the following line below the Update method to create a method named PrintMessage.<\/p>\n

void PrintMessage () {<\/code><\/p>\n

}<\/p>\n

The method\u2019s name is PrintMessage<\/strong>. Notice
\nthat the first letter of each word in the name begins with a capital letter,
\nbut the remaining letters are lowercase. This is the language convention you
\nshould follow whenever creating a method in C#. <\/p>\n

void<\/strong> means
\nthat the method will not return a value. Because the parentheses<\/strong> are
\nempty, the method receives no parameters. There is no return statement using
\nthe return keyword, so (at least for now) the method does not return any value.<\/p>\n

The code we put between the curly brackets
\nis the scope<\/strong> of the method. This is where we write the task that we want
\nthe method to perform whenever its name is called.<\/p>\n

Let\u2019s call the Debug class\u2019s Log method to print a string and the sum of two variables we created in the previous tutorial. <\/p>\n

void PrintMessage () {
<\/code> Debug.Log (\"The sum is: \" + (number1 + number2));
<\/strong>}<\/code><\/p>\n

Now, whenever we call PrintMessage (), the
\nLog method inside PrintMessage () will be executed as we specified.<\/p>\n

Part 3: Testing Methods in Unity<\/h2>\n

Save the script, and open Unity. Press
\nPlay. Only \u201cLet\u2019s go!\u201d will print in the Console. This occurs because
\nwe did not call the PrintMessage method. We need to not only create a method
\nbut also call it. <\/p>\n

Press Stop. Open GameController.cs. Use the following code to call PrintMessage in the Start method, along with the message variable we created last tutorial.<\/p>\n

void Start () {
<\/code> Debug.Log (message);
<\/code> PrintMessage ();
<\/strong>}<\/code><\/p>\n

Now if you save the script and run the
\ngame, the Console will print the value of message and the value of PrintMessage.<\/p>\n

Part 4: Setting Method Parameters in C#<\/h2>\n

What if we want to give PrintMessage
\nparameters? Delete the number1 and number2 variable lines from the
\nGameController class. Instead, use the following code to set number1 and
\nnumber2 to be parameters of PrintMessage.<\/p>\n

void PrintMessage (int number1, int number2) {
<\/code> Debug.Log(\"The sum is: \" + (number1 + number2));
<\/strong>}<\/code><\/p>\n

This changes PrintMessage to receive 2 integers as input, rather than setting the integers on the developer side.<\/p>\n

Part 5: Handling Errors in Unity<\/h2>\n

If you save the script and play the game
\nnow, you will receive the following error message in the Console:<\/p>\n

Assets\/Scripts\/GameController.cs(12,3):
\nerror CS1501: No overload for method \u2018PrintMessage\u2019 takes \u20180\u2019 arguments<\/em><\/p>\n

This message means that in the
\nGameController.cs file, at line 12, PrintMessage has no parameters when it
\nshould. Because we created PrintMessage with parameters, we need to call it
\nwith the same parameters. Use the following format to pass 20 as the number1
\nparameter and 22 as the number2 parameter.<\/p>\n

void Start () {
<\/code> Debug.Log (message)
<\/code> PrintMessage (20, 22);
<\/strong>}<\/code><\/p>\n

This passing of parameters is like passing
\nmessage as the parameter of the Log method. <\/p>\n

Now if you save the script and play the
\ngame, the Console will print \u201cLet\u2019s go!\u201d and \u201cThe sum is
\n42\u201d.<\/p>\n

Part 6: Building a Message<\/h2>\n

Suppose we want to build a message rather than print it. Let\u2019s try this out! Rename PrintMessage \u201cBuildMessage\u201d. Replace void<\/strong> with string. Our method will now return a value as a string rather than an integer.<\/p>\n

string <\/strong>PrintMessage (int number1, int number2) {
<\/code> Debug.Log (\"The sum is: \" + (number1 + number2));
}<\/code><\/p>\n

Instead of calling the Log method to print the sum, use the keyword return<\/strong> to return the message. With the return keywod, we can use the method\u2019s return value anytime by calling the method by name. <\/p>\n

string PrintMessage (int number1, int number2) {
<\/code> return<\/strong> (\"The sum is: \" + (number1 + number2));
}<\/code><\/p>\n

In the Start method, replace the
\nPrintMessage call with a Debug line. Call Log with BuildMessage as a parameter.\n<\/p>\n

Give BuildMessage the parameters 1 as the value for the number1 parameter and 2 as the value for the number2 parameter.<\/p>\n

void Start () {
<\/code> Debug.Log (message);
<\/code> Debug.Log (BuildMessage (number1, number2));
<\/strong>}<\/code><\/p>\n

Calling BuildMessage () will return its
\nreturn value.<\/p>\n

Let\u2019s test our new method! Save the script, and open Unity. Press Play. The Console will print \u201cLet\u2019s go!\u201d and \u201cThe sum is 3\u201d.<\/p>\n

Press Stop, and don\u2019t forget to save your project.<\/p>\n

Review<\/h2>\n

\u2014Team Mammoth from Mammoth Interactive INC. Tutorial by Glauco Pires and Transcribing by Alexandra Kropova<\/em><\/p>\n

More resources on this topic:<\/h2>\n<\/div>\n