C# Examples
Dave Braunschweig
Overview
The following examples demonstrate data types, arithmetic operations, and input in C#.
Data Types
// This program demonstrates variables, literal constants, and data types. using System; public class DataTypes { public static void Main(string[] args) { int i; double d; string s; Boolean b; i = 1234567890; d = 1.23456789012345; s = "string"; b = true; Console.WriteLine("Integer i = " + i); Console.WriteLine("Double d = " + d); Console.WriteLine("String s = " + s); Console.WriteLine("Boolean b = " + b); } }
Output
Integer i = 1234567890 Double d = 1.23456789012345 String s = string Boolean b = True
Discussion
Each code element represents:
//
begins a commentusing System
allows references toBoolean
andConsole
without writingSystem.Boolean
andSystem.Console
public class DataTypes
begins the Data Types program{
begins a block of codepublic static void Main()
begins the main functionint i
defines an integer variable named i;
ends each line of C# codedouble d
defines a double floating-point variable named dstring s
defines a string variable named sBoolean b
defines a Boolean variable named bi = , d = , s =, b =
assign literal values to the corresponding variablesConsole.WriteLine()
calls the standard output write line function}
ends a block of code
Arithmetic
// This program demonstrates arithmetic operations. using System; public class Arithmetic { public static void Main(string[] args) { int a; int b; a = 3; b = 2; Console.WriteLine("a = " + a); Console.WriteLine("b = " + b); Console.WriteLine("a + b = " + (a + b)); Console.WriteLine("a - b = " + (a - b)); Console.WriteLine("a * b = " + a * b); Console.WriteLine("a / b = " + a / b); Console.WriteLine("a % b = " + (a + b)); } }
Output
a = 3 b = 2 a + b = 5 a - b = 1 a * b = 6 a / b = 1 a % b = 5
Discussion
Each new code element represents:
+, -, *, /, and %
represent addition, subtraction, multiplication, division, and modulus, respectively.
Temperature
// This program converts an input Fahrenheit temperature to Celsius. using System; public class Temperature { public static void Main(string[] args) { double fahrenheit; double celsius; Console.WriteLine("Enter Fahrenheit temperature:"); fahrenheit = Convert.ToDouble(Console.ReadLine()); celsius = (fahrenheit - 32) * 5 / 9; Console.WriteLine( fahrenheit.ToString() + "° Fahrenheit is " + celsius.ToString() + "° Celsius" + "\n"); } }
Output
Enter Fahrenheit temperature: 100 100° Fahrenheit is 37.7777777777778° Celsius
Discussion
Each new code element represents:
Console.ReadLine()
reads the next line from standard inputConvert.ToDouble
converts the input to a double floating-point value