CS111 Programming Assignment 2

Instructor: Trish Cornez

1. Explain the OOP meaning of aggregation and composition. Provide an example.
2. How is inheritance specified in Java?
3. Every class in Java has a superclass. Explain the superclass Object. Idenify the member methods of this superclass
4. What does UML stand for? Provide an example of a UML.

Roman numeral : XX
Decimal Value : 20

Code Guidelines

1. Include a default and an explicit constructor.
2. Add the methods shown below:
   • setRomanValue(String r) - resets a roman numeral to a specified string.
   • getRomanValue() - returns the roman numeral as a string.
   • getDecimalValue() - returns the decimal value of the roman numeral.
   • equalTo() - returns true if the roman numeral is equivalent in value to another RomanNumeral object, else returns false.
   • increment() - increments the roman numeral by 1.
3. During Roman times, order did not matter. Use the following decimal values of roman numbers:
   M : 1000
   D : 500
   C : 100
   L : 50
   X : 10
   V : 5
   I : 1
4. Write a test app to verify all the member methods function correctly. You may use the test code below.
   Add a last task to write the results of the test cases to a text file. This will require you to use a try/catch block.

    public class MainApp {

      public static void main(String[] args) {
        System.out.println("Test Application for the RomanNumeral class\n");

        // DECLARE TWO ROMAN NUMERALS USING EXPLICIT AND DEFAULT CONSTRUCTORS.
        RomanNumeral x1 = new RomanNumeral("DXI");
        RomanNumeral x2 = new RomanNumeral();

        // BUILD A STRING CONTAINING ALL THE REQUIRED TEST CASE SCENARIOS
        String testCaseResults = "";

        // TEST 1: VERIFY THE INITIAL VALUES OF x1 AND x2.  COMPARE BOTH OBJECTS
        testCaseResults += "x1 is " + x1.getRomanValue() + " with a decimal value of " + x1.getDecimalValue() + "\n";
        testCaseResults += "x2 is " + x2.getRomanValue() + " with a decimal value of " + x2.getDecimalValue() + "\n";
        testCaseResults += "x1 and x2 are equal?  " + x1.equalTo(x2) + "\n";

        // TEST 2: RESET THE ROMAN VALUE FOR X2 AND COMPARE BOTH OBJECTS AGAIN
        testCaseResults += "\nReset x2:" + "\n";
        x2.setRomanValue("XID");
        testCaseResults += "x2 is now " + x2.getRomanValue() + " with a decimal value of " + x2.getDecimalValue() + "\n";
        testCaseResults += "x1 and x2 are equal?  " + x1.equalTo(x2) + "\n";

        // TEST 3: INCREMENT X2 AND COMPARE BOTH OBECTS AGAIN
        testCaseResults += "\nIncrement x2:" + "\n";
        x2.increment();
        testCaseResults += "x2 is now " + x2.getRomanValue() + " with a decimal value of " + x2.getDecimalValue() + "\n";
        testCaseResults += "x1 and x2 are equal?  " + x1.equalTo(x2) + "\n";

        // DISPLAY THE TEST CASE RESULTS STRING TO THE CONSOLE
        System.out.print(testCaseResults);

        //FINAL TASK: WRITE THE TEST CASE RESULTS TO A TEXT FILE
















      }
    }

  

Create both default and explicit constructors. Create setters and getters for the data members. When coding the default constructor or setter for the denominator, do not allow the denominator to be set to zero. Use the test application shown below to guide you in creating your class and implementing the appropriate class methods. After running this test application.

    public class TestApp {

      public static void main(String[] args) {

        System.out.println("Test Application for the Fraction class");

        // INSTANTIATE ELEVEN FRACTION OBJECTS.
        Fraction f1 = new Fraction();
        Fraction f2 = new Fraction(2, 7);
        Fraction f3 = new Fraction(4, 15);
        Fraction f4 = new Fraction(2, 3);
        Fraction f5 = new Fraction(5, 8);
        Fraction f6 = new Fraction(3, 10);
        Fraction f7 = new Fraction(1, 8);
        Fraction f8 = new Fraction(3, 8);
        Fraction f9 = new Fraction(3, 18);
        Fraction f10 = new Fraction(4, 7);
        Fraction f11 = new Fraction(8, 14);

        // TASK 1: DISPLAY f1, INSTANTIATED BY THE DEFAULT CONSTRUCTOR
        System.out.println("1) f1 = " + f1.toString() + "  (default constructor)");

        // TASK 2: RESET FRACTION f1 AND REDISPLAY IT
        f1.setNum(3);
        f1.setDen(5);
        System.out.println("2) f1 = " + f1.toString() + "  (modified)");

        // TASK 3: ADD FRACTION f2 TO f1
        System.out.print("3) " + f1.toString() + "  +  " + f2.toString() + " = ");
        f1.add(f2);
        System.out.println(f1.toString());

        // TASK 4: SUBTRACT f4 FROM f3
        System.out.print("4) " + f3.toString() + " - " + f4.toString() + " = ");
        f3.subtract(f4);
        System.out.println(f3.toString());

        // TASK 5: MULTIPLY FRACTION f5 BY f6
        System.out.print("5) " + f5.toString() + " * " + f6.toString() + " = ");
        f5.multiply(f6);
        System.out.println(f5.toString());

        // TASK 6: DIVIDE FRACTION f7 BY f8
        System.out.print("6) " + f7.toString() + " " + ((char) 247) + " " + f8.toString() + " = ");
        f7.divide(f8);
        System.out.println(f7.toString());

        // TASK 7: REDUCE FRACTION f9
        System.out.print("7) The fraction " + f9.toString() + " can be reduced to ");
        f9.reduce();
        System.out.println(f9.toString());

        // TASK 8: COMPARE FRACTIONS f10 and f11
        System.out.print("8) " + f10.toString() + " == " + f11.toString() + ": " + f10.isEqual(f11));
      }

    }