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%2B%2B_Programming #include <iostream> using namespace std; double getTemperature(string label); double calculateCelsius(double fahrenheit); double calculateFahrenheit(double celsius); void displayResult(double temperature, string fromLabel, double result, string toLabel); int main() { // main could either be an if-else structure or a switch-case structure char choice; double temperature; double result; cout << "Enter F to convert to Fahrenheit or C to convert to Celsius:" <> choice; // 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 { cout << "You must enter C to convert to Celsius or F to convert to Fahrenheit!" << endl; } // 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: cout << "You must enter C to convert to Celsius or F to convert to Fahrenheit!" << endl; } } double getTemperature(string label) { double temperature; cout << "Enter " << label << " temperature:" <> temperature; return temperature; } double calculateCelsius(double fahrenheit) { double celsius; celsius = (fahrenheit - 32) * 5 / 9; return celsius; } double calculateFahrenheit(double celsius) { double fahrenheit; fahrenheit = celsius * 9 / 5 + 32; return fahrenheit; } void displayResult(double temperature, string fromLabel, double result, string toLabel) { cout << temperature << "° " << fromLabel << " is " << result << "° " << toLabel << endl; }
Output
Enter C to convert to Celsius or F to convert to Fahrenheit: c Enter Fahrenheit temperature: 100 100° Fahrenheit is 37.7778° 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.