Question

Create a Ball enum with the following weights and diameters and must include methods of getCircumference() and getVolume() to calculate the circumference and the volume of a ball (2 points)

BASEBALL(149, 73)

       BASKETBALL(624, 239)

       FOOTBALL(450 , 216)

       GOLF(46, 43)

       POOL(156, 60)

       SOFTBALL(180, 97)

       TENNIS(59, 64)

       VOLLEYBALL(260, 218)

Test the enum in the main by printing out the name of each ball with its weight and diameter (see example: print out of enum). In addition, print out the circumference of a golf and the volume of baseball in the main class (see example: print out of the circumference and the volume) (1 points)

              example: print out of enum

BASEBALL       149 g 73 mm

BASKETBALL     624 g 239 mm

FOOTBALL       450 g 216 mm

GOLF            46 g 43 mm

POOL           156 g 60 mm

SOFTBALL       180 g 97 mm

TENNIS          59 g 64 mm

       VOLLEYBALL     260 g 218 mm

              example: print out of the circumference and the volume

The circumferent of a golf = 135.02 mm

       The volume of a baseball = 203688.82 mm^3

Create a Rational class  (A rational no. is a number that can be expressed in the form of p/q, where p,q are integers with q !=0 and p and q have no common divisor) . Rational class must include methods of multiply(), divide(), plus(), minus() to do calculation with two rational numbers. In addition, include a method to simplify a rational number to its lowest form, and a toString() method for the lowest forms and its decimal form (see example: print out of the calculation) (4 points)

Test with the following 4 rational numbers in the main

r1 = new Rational(baseball weight, basketball weight)

r2 = new Rational(football weight, golf weight)

r3 = new Rational(pool diameter, softball diameter)

r4 = new Rational(tennis diameter, volleyball diameter)

             In addition, print & simplify the following rational number and calculations (2 points)

15 / 40

r1 + r2

r2 – r3

r3 * r4

r4 / r1

              example: print out of the calculation

15/40 = 3/8 = 0.38

(149/624) + (450/46) = 143827/14352 = 10.02

(450/46) - (60/97) = 20445/2231 = 9.16

(60/97) * (64/218) = 1920/10573 = 0.18

(64/218) / (149/624) = 19968/16241 = 1.23

Answer 1

//Ball enum

public enum Ball {

      // Ball type

      BASEBALL(149, 73), BASKETBALL(624, 239), FOOTBALL(450, 216), GOLF(46, 43), POOL(156, 60), SOFTBALL(180,

                  97), TENNIS(59, 64), VOLLEYBALL(260, 218);

      // Variables

      private int weight;

      private int diameter;

      /**

      * Parameterized constructor

      *

      * @param weight

      *            - weight of the ball

      * @param diameter

      *            - diameter of the ball

      */

      private Ball(int weight, int diameter) {

            this.weight = weight;

            this.diameter = diameter;

      }

     

      /**

      * Returns the weight of the ball

      */

      public int getWeight() {

            return weight;

      }

      /**

      * Returns the diameter of the ball

      */

      public int getDiameter() {

            return diameter;

      }

      /**

      * Returns the circumference of the ball

      */

      public double getCircumference() {

            return 3.14 * this.diameter;

      }

      /**

      * Returns the volume of the ball

      */

      public double getVolume() {

            double radius = this.diameter / 2.0;

            return ((4.0 / 3.0) * Math.PI * radius * radius * radius);

      }

      /**

      * Returns the string representation of ball

      */

      public String display() {

            return String.format("%-15s", name()) + "\t" + this.weight + " g " + this.diameter + " mm";

      }

}

/**

* This represents a Rational class. A rational no. is a number that can be

* expressed in the form of p/q, where p,q are integers with q !=0 and p and q

* have no common divisor

*/

import java.text.DecimalFormat;

public class Rational {

      // Instance variable

      private int numerator;

      private int denominator;

      /**

      * Default Constructor

      */

      public Rational() {

            this(1, 1);

      }

      /**

      * Parameterized constructor

      *

      * @param numerator

      *            - numerator of the Rational number

      * @param denominator

      *            - denominator of the Rational number

      */

      public Rational(int numerator, int denominator) {

            this.numerator = numerator;

            this.denominator = denominator;

      }

      /**

      * Simplifies this rational number to it simplest form

      */

      public void simplify() {

            if (this.numerator == this.denominator) {

                  this.numerator = 1;

                  this.denominator = 1;

            } else {

                  // Find minimum between numerator and denominator

                  int min = (this.numerator < this.denominator) ? this.numerator : this.denominator;

                  // Reduce the fraction by dividing the numerator and denominator by

                  // values [2 to min]

                  for (int i = 2; i <= min; i++) {

                        // Divide by i only if numerator and denominator, both, are

                        // divisible by i

                        while (((this.numerator % i) == 0) && ((this.denominator % i) == 0)) {

                              this.numerator /= i;

                              this.denominator /= i;

                        }

                  }

            }

      }

      /**

      * Returns the numerator

      */

      public int getNumerator() {

            return numerator;

      }

      /**

      * Returns the denominator

      */

      public int getDenominator() {

            return denominator;

      }

      /**

      * Returns the rational number in decimal form

      */

      public String decimalForm() {

            // Create decimal format to display double values

            DecimalFormat df = new DecimalFormat("##0.00");

           

            // Get decimal form

            double result = (getNumerator() * 1.0) / getDenominator();

                       

            return "" + df.format(result);

      }

      /**

      * Returns the simplified rational number as string (numerator /

      * denominator)

      */

      public String simplifiedForm() {

            // Create a new rational number having numerator and denominator as this

            // rational number

            Rational r = new Rational(this.getNumerator(), this.getDenominator());

            // Simplify r

            r.simplify();

            // Return the simplified form as string

            return r.getNumerator() + "/" + r.getDenominator();

      }

      /**

      * Returns the rational number as string (numerator / denominator)

      */

      @Override

      public String toString() {

            return getNumerator() + "/" + getDenominator();

      }

      /**

      * Performs the operation specified by the parameter

      *

      * @param r

      *            - rational number

      * @param operation

      *            - operation to be performed (+, -, *, /)

      * @return - Returns the result as a rational number

      */

      private Rational operate(Rational r, String operation) {

            Rational result = null;

            int n1 = this.getNumerator();

            int n2 = r.getNumerator();

            // Find result of operation

            if (operation.equals("*")) { // Multiply

                  result = new Rational(this.getNumerator() * r.getNumerator(), this.getDenominator() * r.getDenominator());

            } else if (operation.equals("/")) { // Divide

                  result = new Rational(this.getNumerator() * r.getDenominator(), this.getDenominator() * r.getNumerator());

            } else { // For addition and subtraction

                  if (this.getDenominator() != r.getDenominator()) {

                        // Cross multiply the fractions

                        // This way the denominators will be same

                        n1 = this.getNumerator() * r.getDenominator();

                        n2 = r.getNumerator() * this.getDenominator();

                  }

                  if (operation.equals("+"))

                        result = new Rational(n1 + n2, this.getDenominator() * r.getDenominator());

                  else if (operation.equals("-"))

                        result = new Rational(n1 - n2, this.getDenominator() * r.getDenominator());

            }

            return result;

      }

      /**

      * Adds rational number r to this rational number

      *

      * @param r

      *            - rational number to which this rational number is to be added

      */

      public Rational plus(Rational r) {

            return operate(r, "+");

      }

      /**

      * Subtracts rational number r from this rational number

      *

      * @param r

      *            - rational number which is to be subtracted from this rational

      *            number

      */

      public Rational minus(Rational r) {

            return operate(r, "-");

      }

      /**

      * Multiplies rational number r to this rational number

      *

      * @param r

      *            - rational number which is to be multiplied by this rational

      *            number

      */

      public Rational multiply(Rational r) {

            return operate(r, "*");

      }

      /**

      * Divides this rational number by rational number r

      *

      * @param r

      *            - rational number which divides this rational number

      */

      public Rational divide(Rational r) {

            return operate(r, "/");

      }

}

/**

* This class tests the Ball enum.

*/

import java.text.DecimalFormat;

public class EnumTest {

      public static void main(String[] args) {

            // Display all Ball

            for (Ball b : Ball.values()) {

                  System.out.println(b.display());

            }

            // Create decimal format to display double values

            DecimalFormat df = new DecimalFormat("##0.00");

            // Display circumference of a golf ball

            double circumference = Ball.GOLF.getCircumference();

            System.out.println("\nThe circumference of a golf = " + df.format(circumference) + " mm");

            // Display volume of a baseball

            double vol = Ball.BASEBALL.getVolume();

            System.out.println("\nThe volume of a baseball = " + df.format(vol) + " mm^3");

            // Test Rational number class

            System.out.println("\nTESTING RATIONAL CLASS");

           

            // Create a Rational Object

            Rational r = new Rational(15, 40);

           

            // Display rational number

            System.out.println(r + " = " + r.simplifiedForm() + " = "+ r.decimalForm());

            // Create rational numbers

            Rational r1 = new Rational(Ball.BASEBALL.getWeight(), Ball.BASKETBALL.getWeight());

            Rational r2 = new Rational(Ball.FOOTBALL.getWeight(), Ball.GOLF.getWeight());

            Rational r3 = new Rational(Ball.POOL.getDiameter(), Ball.SOFTBALL.getDiameter());

            Rational r4 = new Rational(Ball.TENNIS.getDiameter(), Ball.VOLLEYBALL.getDiameter());

           

            // r1 + r2

            Rational addResult = r1.plus(r2);

            System.out.println("(" + r1 + ") + (" + r2 + ") = " + addResult.simplifiedForm() + " = " + addResult.decimalForm());

           

            // r2 – r3

            Rational subResult = r2.minus(r3);

            System.out.println("(" + r2 + ") + (" + r3 + ") = " + subResult.simplifiedForm() + " = " + subResult.decimalForm());

           

            // r3 * r4

            Rational prodResult = r3.multiply(r4);

            System.out.println("(" + r3 + ") + (" + r4 + ") = " + prodResult.simplifiedForm() + " = " + prodResult.decimalForm());

           

            // r4 / r1

            Rational divResult = r4.divide(r1);

            System.out.println("(" + r4 + ") + (" + r1 + ") = " + divResult.simplifiedForm() + " = " + divResult.decimalForm());

      }

}

SAMPLE OUTPUT: