C# Examples
Dave Braunschweig
Temperature
// This program asks the user to select Fahrenheit or Celsius conversion
// and input a given temperature. Then the program converts the given
// temperature and displays the result.
//
// References:
// https://www.mathsisfun.com/temperature-conversion.html
// https://en.wikibooks.org/wiki/C_Sharp_Programming
using System;
public class MainClass
{
public static void Main(String[] args)
{
// main could either be an if-else structure or a switch-case structure
string choice;
double temperature;
double result;
Console.WriteLine("Enter F to convert to Fahrenheit or C to convert to Celsius:");
choice = Console.ReadLine();
// if-else approach
if (choice == "C" || choice == "c")
{
temperature = GetTemperature("Fahrenheit");
result = CalculateCelsius(temperature);
DisplayResult(temperature, "Fahrenheit", result, "Celsius");
}
else if (choice == "F" || choice == "f")
{
temperature = GetTemperature("Celsius");
result = CalculateFahrenheit(temperature);
DisplayResult(temperature, "Celsius", result, "Fahrenheit");
}
else
{
Console.WriteLine("You must enter C to convert to Celsius or F to convert to Fahrenheit!");
}
// switch-case approach
switch(choice)
{
case "C":
case "c":
temperature = GetTemperature("Fahrenheit");
result = CalculateCelsius(temperature);
DisplayResult(temperature, "Fahrenheit", result, "Celsius");
break;
case "F":
case "f":
temperature = GetTemperature("Celsius");
result = CalculateFahrenheit(temperature);
DisplayResult(temperature, "Celsius", result, "Fahrenheit");
break;
default:
Console.WriteLine("You must enter C to convert to Celsius or F to convert to Fahrenheit!");
break;
}
}
private static double GetTemperature(string label)
{
string input;
double temperature;
Console.WriteLine("Enter " + label + " temperature:");
input = Console.ReadLine();
temperature = Convert.ToDouble(input);
return temperature;
}
private static double CalculateCelsius(double fahrenheit)
{
double celsius;
celsius = (fahrenheit - 32) * 5 / 9;
return celsius;
}
private static double CalculateFahrenheit(double celsius)
{
double fahrenheit;
fahrenheit = celsius * 9 / 5 + 32;
return fahrenheit;
}
private static void DisplayResult(double fahrenheit, string fromLabel, double celsius, string toLabel)
{
Console.WriteLine(fahrenheit.ToString() + "° " + fromLabel + " is " + celsius.ToString() + "° " + toLabel);
}
}
Output
Enter C to convert to Celsius or F to convert to Fahrenheit: c Enter Fahrenheit temperature: 100 100° Fahrenheit is 37.7777777777778° Celsius Enter C to convert to Celsius or F to convert to Fahrenheit: f Enter Celsius temperature: 100 100° Celsius is 212° Fahrenheit Enter C to convert to Celsius or F to convert to Fahrenheit: x You must enter C to convert to Celsius or F to convert to Fahrenheit.
