C# : variables! Useful info, little tips and advice
Variables are crucial for writing code. There are some standard things that are best to know and use right away: Unity and C # are “CASE SENSITIVE”. So any lowercase or uppercase matters. As a practice, variables are ALWAYS written in lowercase. For example, the speed variable will be written like this
Variables are often made up of several words, and the way to write them is this: if for example, we have to set the speed of the Player, the variable will be
First word ALWAYS lowercase, but the first letter of the second word will be CAPITAL.
If it were three words, the third word would have a capital first, and so on
Another point: PRIVATE VARIABLES need an underscore in front
same, but with underscore
Sometimes we can see variables written like this
It means it’s PRIVATE.
private int number = 5;
int number = 5;
EXACTLY SAME THING
One of the more important thing is something called SCOPE.
What is the SCOPE of variables?
This is one of the crucial thing about variables.
Here we have a simple C# script.
If we create a TOP variable of this class, the SCOPE of the variable is in the whole Class.
This means that in every part of this class we can ACCESS the variable.
Example : I create a int number, then I try to access to it from Start and Update
But if I have a method, and inside I create a variable
If I try to access a or b OUTSIDE THIS METHOD, I can’t.
Because the PURPOSE of these two variables is WITHIN THIS METHOD. Out of here, they don’t exist!
In fact, if we try
But inside Sum() i can access to number
In a simpler way, let’s think this way: the curly brackets represent the SCOPE OF VARIABLES.
In our case, “number” is between the two braces that enclose the whole class,
“a” and “b” instead are between the two braces that enclose ONLY THE SUM () METHOD.
Go deep in this topic!
First, we can set the variables value directly in the inspector.
If we have different value in the script and write new one in the inspector, we can reset value simply click this little icon and reset.
Now try to change PUBLIC to PRIVATE and see what happen.
When back in Unity, the variable is not visible!
Everything works fine, the speed value is set to the script, but we can’t adjust that in the inspector.
This because we set variable to PRIVATE and only “Player” can access to it, nothing outside.
The logic is really simple, if we need something outside the Player that has access to that variable, we set it to public, otherwise, is always better to private.
The last tip introduces a concept : “attribute”.
The attribute is something you can write above the variable in square brackets and give a sort of “customization” at that variable.
For now, i’m not go to deep in this topic, we will talk more when use it for “Unity editor” or some particular customization, but is good to know that if we want create a private variable and we want see in the inspector, the method and the syntax is this
With this, Unity SERIALIZE the data and we can see in the inspector. So, even if the variables are private, with this we can see and overwrite in the inspector the value of them.