/* T01n18.java -- A Fraction class.  A fraction has a numerator and a
 * denominator.  This class has a pair of constructors:
 *
 *    Fraction ()         -- Constructs the fraction 0/1
 *    Fraction (int, int) -- accepts initial numerator and denominator
 *
 * And several instance methods:
 *
 *    "Getters" ( void getNumerator(int)  and  void getDenominator(int) )
 *    "Setters" ( void setNumerator(int)  and  void setDenominator(int) )
 *    double asDouble() -- return the fraction as a value of type double
 *    String asString() -- convert the fraction to a "X / Y" format string
 *    Fraction multiplyBy(int) -- mult. X/Y by Z to produce XZ/Y
 *    Fraction multiplyBy(Fraction) -- mult X/Y by W/Z to get XW/YZ
 *
 * Note #1:  The overloading of the multiplyBy name; this shows that we can
 * overload more than just the constructors.
 *
 * Note #2:  This doesn't demonstrate the level of documentation we'll
 * expect from you!  We'll have guidelines for you to follow when the time
 * comes.
 */

class Fraction
{

            /* Instance Variables, a.k.a. Data Members */

    private int numerator,    // Top number of the fraction
                denominator;  // Bottom number of the fraction


            /* Constructors */
             
    public Fraction ()
    {
        numerator = 0;
        denominator = 1;
    }

    public Fraction (int numerator, int denominator)
    {
        this.numerator = numerator;    // "this" references the current object
        this.denominator = denominator;
    }


            /* Public Methods */

    public int getNumerator ()
    {
        return numerator;
    }

    public int getDenominator ()
    {
        return denominator;
    }

    public void setNumerator (int newNumerator)
    {
        numerator = newNumerator;
    }

    public void setDenominator (int newDenominator)
    {
        denominator = newDenominator;
    }

    public double asDouble ()
    {
        return (double)numerator / denominator;
    }

    public String asString ()
    {
        return numerator + "/" + denominator;
    }

    public Fraction multiplyBy (int multiplier)
    {
        return new Fraction(numerator * multiplier,denominator);
    }

    public Fraction multiplyBy (Fraction multiplier)
    {
        Fraction result;
        int      newNumerator,    // the product of the existing numerators
                 newDenominator;  // the product of the existing denominators

        newNumerator = numerator * multiplier.getNumerator();
        newDenominator = denominator * multiplier.getDenominator();
        result = new Fraction(newNumerator,newDenominator);
        return result;
    }

} // class Fraction


public class T01n18
{
    public static void main (String [] args)
    {
        Fraction myFraction,         // these fractions are hard to name...
                 myOtherFraction,
                 anotherFraction,
                 yetAnotherFraction;

        myFraction = new Fraction (3,4);           
        myOtherFraction = new Fraction (2,3);   

        System.out.println(myFraction.asDouble());

        anotherFraction = myOtherFraction.multiplyBy(4);
        System.out.println(anotherFraction.asString());

        yetAnotherFraction = myOtherFraction.multiplyBy(myFraction);
        System.out.println(yetAnotherFraction.asString());
    }
}