Chapter 2. C# Language Basics

In this chapter, we introduce the basics of the C# language.


All programs and code snippets in this and the following two chapters are available as interactive samples in LINQPad. Working through these samples in conjunction with the book accelerates learning in that you can edit the samples and instantly see the results without needing to set up projects and solutions in Visual Studio.

To download the samples, click the Samples tab in LINQPad and then click “Download more samples.” LINQPad is free—go to

A First C# Program

Here is a program that multiplies 12 by 30 and prints the result, 360, to the screen. The double forward slash indicates that the remainder of a line is a comment:

using System;                     // Importing namespace

class Test                        // Class declaration
  static void Main()              //   Method declaration
    int x = 12 * 30;              //     Statement 1
    Console.WriteLine (x);        //     Statement 2
  }                               //   End of method
}                                 // End of class

At the heart of this program lie two statements. Statements in C# execute sequentially. Each statement is terminated by a semicolon:

    int x = 12 * 30;
    Console.WriteLine (x);

The first statement computes the expression 12 * 30 and stores the result in a local variable, named x, which is an integer type. The second statement calls the Console class’s WriteLine method, to print the variable x to a text window on the screen.

A method performs an action in a series of statements, called a statement block—a pair of braces containing zero or ...

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