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Programming Fundamentals/Variable Examples CSharp
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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 comment
using System allows references to Boolean and Console without writing System.Boolean and System.Console
public class DataTypes begins the Data Types program
{ begins a block of code
public static void Main() begins the main function
int i defines an integer variable named i
; ends each line of C# code
double d defines a double floating-point variable named d
string s defines a string variable named s
Boolean b defines a Boolean variable named b
i = , d = , s =, b = assign literal values to the corresponding variables
Console.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 input
Convert.ToDouble converts the input to a double floating-point value
References
Wikiversity: Computer Programming