Specifying by Type on Godot.

For people like me, it can be very confusing to have a variable not be specified by type.
Gladly, Godot contains ways of specifying scripts and variables by type, and I will show you how.

Assigning Type to Variables

Variables generally are written with var preceding the name of the variable, like bellow:

var Name

That is still vague about what kind of variable that is, beside Name implies that a string
will be there, which might not be the case.

Beside, can be set a string value to it.

var Name = ""

Hm, yeah, there's a string there, but still not enough to specify what kind of variable that is.
I mean, you can place a number there or something, and it will still be okay for Name variable.
That's why you can add specification right after the variable name, to tell which kind of
value it will take.

var Name : String = ""

There, now that variable is bound to receive only String type variables. It's not necessary to assign a default value, by the way.

Specifying variable type on method arguments.

Methods also make use of variables with unspecified types, but at least in this case, might be 

troublesome depending on use of the method, and even more troublesome if it's related to specific object types.
For methods like the one bellow, it's not much of a problem.

func Sum(a, b):
    print_debug(str(a + b))
    pass

 

Normally, you assign them like this.

You can specify a type, by placing a double dot, with the type right next to variable name.

func Sum(a: int, b: int):
    print_debug(str(a + b))
    pass

The specification can be used for types and also object types.

The method above doesn't seems very functional, though. The method does the sum, but 
instead of returning a value, it prints a message on the log with the result of the sum.

Lets add a return type to it.

func Sum(a: int, b: int) -> int:
    return a + b

There, now the method will return a integer variable, which will be the sum of a and b.

Do notice that pass is not the same as return, by the way. I discovered that after many bugs.

Assigning Classes to Script

Assigning classes to a script is very useful if you want to reference an object by type.
Normally, a method will not know what type of the value its arguments is calling, 

much less if you're using as argument a method.

 

Beside you can still type in the code to methods and variables of that object from the 

argument, which will still run the game normally if you typed correctly, the spell 

checking of Godot will not help you find those methods.

That's where turning a script into a class enters into. That will recognize that script 

type, and allow you to assign them as variable types and method arguments/return 

values.

 

To turn a script into a class, it's as simple as specifying it on the top of the script.

class_name NameOfClass

That's about it, and you can name the class anything you want, but probably
there's some rules regarding that, though.

Now you can find out if an object is of that class type...

if (value is NameOfClass):

...Or specify if that value is of a certain class type...

var MyNameOfClass = value as NameOfClass

...Or even specifying variable types...

var MyNameOfClass : NameOfClass

...Or simply setting argument of methods, or even return values of their type.

func NameOfClassClub(newMember: NameOfClass) -> NameOfClass:

Finishing

There it goes. Here I show how to specify types on Godot, and also how to assign a 

Class Name to objects.

I hope this tutorial was helpful for you.