Chapter 2. C# Language Basics
In this chapter, we explain a simple C# program and introduce the basics of the C# language.
A First C# Program
Here is a simple C# program:
namespace FirstProgram { using System; class Example { static void Main () { Console.WriteLine ("Hello world!"); } } }
A C# program is composed of types (typically classes) that we organize
into namespaces. Each type contains function members (typically methods and
properties), as well as data members (typically fields). Methods contain a
series of statements that are executed sequentially. In our program, we define
a class named Example
that contains a method named Main
,
which has a single statement that writes Hello
world!
to
the console window. C# recognizes this method as
the default entry point of execution, so that’s where the program begins.
The Console
class encapsulates standard input/output
functionality, providing methods such as WriteLine
. To
use types from another namespace, use the using
directive.
Since the Console
class resides in the System
namespace,
we go via System
; similarly, types from other namespaces
could use our Example
class by using FirstProgram
.
In C#, there are no standalone functions; they are always associated with a type, or, as we will see, instances of that type. Our program is simple, and makes use of only static members, which means the member is associated with its type, rather than instances of its type. In addition, we make use of only void methods, which means these methods do ...
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