C#

Appeared in:
2002
Influenced by:
Influenced:
Paradigm:
Typing discipline:
Versions and implementations (Collapse all | Expand all):
Programming language

C# is a modern general-purpose programming language designed for CLI (Common Language Infrastructure) specification.

Language development started in 1999 under the name Cool (“C-like Object Oriented language”). It was renamed to “C#” later to avoid trademark conflict and to emphasis both its origin from C++ and its superiority compared to it.

C# 1.0 was released in 2002 by Microsoft.

The official standards of the language are ECMA-334 and ISO/IEC 23270:2006. Microsoft Visual C# is C# reference implementation, though there exist several other implementations.

C# was designed as a simple modern language similar to C++ which should implement a number of features which improve safety and robustness of code as well as development efficiency and code portability.

C# is still a relatively young language, but it gains popularity fast.

Examples:

Hello, World!:

Example for versions Microsoft Visual C# 2008, gmcs 2.0.1 
using System;

class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine("Hello, World!");
    }
}

Factorial:

Example for versions Microsoft Visual C# 2008, gmcs 2.0.1

This example uses recursive factorial definition. 

using System;

class Program
{
    static long Factorial(int n)
    {
        if (n == 0)
            return 1;
        else
            return n * Factorial(n - 1);
    }
    static void Main(string[] args)
    {
        for (int i = 0; i < 17; i++)
            Console.WriteLine("{0}! = {1}",i,Factorial(i));
    }
}

Fibonacci numbers:

Example for versions Microsoft Visual C# 2008, gmcs 2.0.1

This example uses recursive definition of Fibonacci numbers. 

using System;

class Program
{
    static long Fibonacci(int n)
    {
        if (n < 3)
            return 1;
        else
            return Fibonacci(n - 1) + Fibonacci(n - 2);
    }
    static void Main(string[] args)
    {
        for (int i = 1; i < 17; i++)
            Console.Write("{0}, ", Fibonacci(i));
        Console.WriteLine("...");
    }
}

Quadratic equation:

Example for versions Microsoft Visual C# 2008, gmcs 2.0.1 
using System;

class Program
{
    static void Main(string[] args)
    {
        int A, B, C, D;
        try
        {   Console.Write("A = ");
            A = Convert.ToInt32(Console.ReadLine());
            Console.Write("B = ");
            B = Convert.ToInt32(Console.ReadLine());
            Console.Write("C = ");
            C = Convert.ToInt32(Console.ReadLine());
        }
        catch
        {   Console.WriteLine("Invalid input");
            return;
        }
        if (A == 0)
        {   Console.WriteLine("Not a quadratic equation.");
            return;
        }
        D = B * B - 4 * A * C;
        if (D == 0)
            Console.WriteLine("x = {0}", -B / 2.0 / A);
        else if (D > 0)
            Console.WriteLine("x1 = {0}\nx2 = {1}", (-B + Math.Sqrt(D)) / 2 / A, (-B - Math.Sqrt(D)) / 2 / A);
        else
            Console.WriteLine("x1 = ({0},{1})\nx2 = ({0},-{1})", -B/2.0/A, Math.Sqrt(-D)/2/A);
    }
}