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Engineering LibreTexts

3.16: Swift Examples

  • Page ID
    10635
  • Temperature

    // This program asks the user for a Fahrenheit temperature, 
    // converts the given temperature to Celsius,
    // and displays the results.
    //
    // References:
    //     https://www.mathsisfun.com/temperature-conversion.html
    //     https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/TheBasics.html
    
    func getFahrenheit() -> Double {
        var fahrenheit: Double
        
        print("Enter Fahrenheit temperature:")
        fahrenheit = Double(readLine(strippingNewline: true)!)!
        
        return fahrenheit
    }
    
    func calculateCelsius(fahrenheit: Double) -> Double {
        var celsius: Double
        
        celsius = (fahrenheit - 32) * 5 / 9
        
        return celsius
    }
    
    func displayResult(fahrenheit: Double, celsius: Double) {
        print(String(fahrenheit) + "° Fahrenheit is " + String(celsius) + "° Celsius")
    }
    
    func main() {
        var fahrenheit: Double
        var celsius: Double
        
        fahrenheit = getFahrenheit()
        celsius = calculateCelsius(fahrenheit:fahrenheit)
        displayResult(fahrenheit:fahrenheit, celsius:celsius)
    }
    
    main()
    

    Output

    Enter Fahrenheit temperature:
     100
    100.0° Fahrenheit is 37.7777777777778° Celsius