Game Development Reference
In-Depth Information
obliged to group them in methods.
Every instruction in a program belongs to a
method.
Grouping instructions is done with braces (
{
and
}
). Such a block of instruc-
tions grouped together is called the
body
of a method. Above the body, we write the
header
of the method. An example of a method header is:
static void
Main()
The header contains, among other things, the
name
of the method (in this case
Main
).
As a programmer, you may choose any name for a method. However, every program
must
have exactly one method named
Main
.The
Main
method tells the compiler
which instructions should be executed when the program starts. We have seen that
the game loop consists of two parts:
Update
and
Draw
. In programming terms, these
parts are modeled as
methods
, as you can see in the example program. Inside these
methods, we then place the instructions that we want to execute in order to update
or draw the game world.
3.3.4 A Class: A Group of Methods with a Name
Because C# is also an object-oriented language, methods, in turn, are grouped in
classes
. If you look more carefully at the
BasicGame
program, you see that there are
five methods grouped in the class called
BasicGame
. Just like instructions, methods
cannot be arbitrarily placed in a program. Instructions need to be part of the body
of a method, and methods
must
be part of a class. Grouping methods is also done
by using braces. This means that around our methods we place braces (this is called
the
body
of the class) and above it we see the
header
of the class:
class
BasicGame : Game
The class header consists of the word
class
and after that, the name of the class. As
a programmer, you are allowed to choose any name for your class, which in this
case is
BasicGame
. Sometimes, a class is a specialized version of another class. This
is the case with our
BasicGame
class: we indicate behind the class name that we are
building a
game
, and not a console application or a web application. We do this by
using a colon and the name of another class (
Game
). We will come back to this later
on.
3.3.5 Syntax Diagrams
Programming in a language such as C# can be quite difficult if you do not know the
rules of the language. In this topic, we will use so-called
syntax diagrams
to explain
how the language is structured. The
syntax
of a programming language refers to the
