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Fraction file:
/*************************************************************************************
*
* This class represents a fraction whose numerator and denominator are integers.
*
* Requirements:
* 1. Implement interfaces: FractionInterface and Comparable (i.e. compareTo())
* 2. Implement methods equals() and toString() from class Object
* 3. Must work for both positive and negative fractions
* 5. Must simplify result fraction for operations add(), subtract(), multiply() and divide()
* 6. Must throw FractionException objects in case of errors,
* do not throw other exception objects
* 7. Must not add new or modify existing data fields
* 8. Must not add new public methods
* 9. May add private methods
*
* Hints:
*
* 1. To reduce a fraction such as 4/8 to lowest terms, you need to divide both
* the numerator and the denominator by their greatest common denominator.
* The greatest common denominator of 4 and 8 is 4, so when you divide
* the numerator and denominator of 4/8 by 4, you get the fraction 1/2.
* The recursive method GCD() which finds the greatest common denominator of
* two positive integers is given (see code)
*
* 2. You need to downcast reference parameter FractionInterface to Fraction if
* you want to use it as Fraction. See add, subtract, multiply and divide methods
*
* 3. Use "this" to access this object if it is needed
*
************************************************************************************/
package PJ1;
public class Fraction implements FractionInterface, Comparable<Fraction>
{
// integer numerator and denominator
private int num;
private int den;
public Fraction()
{
// implement this method!
// set fraction to default = 0/1
} // end default constructor
public Fraction(int num, int den)
{
// implement this method!
// return FractionException if initial denominator is 0
} // end constructor
public void setFraction(int num, int den)
{
// implement this method!
// return FractionException if initial denominator is 0
} // end setFraction
public FractionInterface simplify()
{
// implement this method!
//
// 1. Adjusts the signs of the num and den so that the num's sign
// is the sign of the fraction and the den's sign is positive value.
// 2. Reduce the number: compute GCD of num & den
// num/GCD and den/GCD
// return this fraction object
return null;
}
public double toDouble()
{
// implement this method!
// return double floating point value
return 0.0;
} // end toDouble
public FractionInterface add(FractionInterface secondFraction)
{
// implement this method!
// a/b + c/d is (ad + cb)/(bd)
return null;
} // end add
public FractionInterface subtract(FractionInterface secondFraction)
{
// implement this method!
// a/b - c/d is (ad - cb)/(bd)
return null;
} // end subtract
public FractionInterface multiply(FractionInterface secondFraction)
{
// implement this method!
// a/b * c/d is (ac)/(bd)
return null;
} // end multiply
public FractionInterface divide(FractionInterface secondFraction)
{
// implement this method!
// return FractionException if secondFraction is 0
// a/b / c/d is (ad)/(bc)
return null;
} // end divide
public boolean equals(Object other)
{
// implement this method!
return false;
} // end equals
public int compareTo(Fraction other)
{
// implement this method!
return 0;
} // end compareTo
public String toString()
{
return num + "/" + den;
} // end toString
//-----------------------------------------------------------------
// private methods start here
//-----------------------------------------------------------------
/** Task: Computes the greatest common divisor of two integers.
* @param integerOne an integer
* @param integerTwo another integer
* @return the greatest common divisor of the two integers */
private int GCD(int integerOne, int integerTwo)
{
int result;
if (integerOne % integerTwo == 0)
result = integerTwo;
else
result = GCD(integerTwo, integerOne % integerTwo);
return result;
} // end GCD
// YOU CAN ADD MORE PRIVATE METHODS HERE.....
//-----------------------------------------------------------------
// Here are my tests:
//-----------------------------------------------------------------
public static void main(String[] args)
{
FractionInterface firstOperand = null;
FractionInterface secondOperand = null;
FractionInterface result = null;
double doubleResult = 0.0;
Fraction nineSixteenths = new Fraction(9, 16); // 9/16
Fraction oneFourth = new Fraction(1, 4); // 1/4
System.out.println("\n=========================================\n");
firstOperand = new Fraction();
firstOperand.setFraction(20,-35);
System.out.println("1. Set fraction is \t\t" + firstOperand);
System.out.println("\tExpected result :\t20/-35\n");
System.out.print("2. Simplify fraction is \t" + firstOperand );
FractionInterface tmp = firstOperand.simplify();
System.out.println(" " + tmp);
System.out.println("\tExpected result :\t20/-35 -4/7\n");
firstOperand = new Fraction(-51, -36);
System.out.print("3. Simplify fraction is \t" + firstOperand);
tmp = firstOperand.simplify();
System.out.println(" " + tmp);
System.out.println("\tExpected result :\t-51/-36 17/12\n");
firstOperand = new Fraction(250, -35);
System.out.print("4. Simplify fraction is \t" + firstOperand );
tmp = firstOperand.simplify();
System.out.println(" " + tmp);
System.out.println("\tExpected result :\t250/-35 -50/7\n");
System.out.println("\n=========================================\n");
// 7/8 + 9/16
firstOperand = new Fraction(7, 8);
result = firstOperand.add(nineSixteenths);
System.out.print("5. The sum of " + firstOperand + " and " +
nineSixteenths + " is \t\t" + result);
System.out.println("\n\tExpected result :\t\t23/16\n");
// 9/16 - 7/8
firstOperand = nineSixteenths;
secondOperand = new Fraction(7, 8);
result = firstOperand.subtract(secondOperand);
System.out.print("6. The difference of " + firstOperand +
" and " + secondOperand + " is \t" + result);
System.out.println("\n\tExpected result :\t\t-5/16\n");
// 15/-2 * 1/4
firstOperand = new Fraction(15, -2);
result = firstOperand.multiply(oneFourth);
System.out.print("7. The product of " + firstOperand +
" and " + oneFourth + " is \t" + result);
System.out.println("\n\tExpected result :\t\t-15/8\n");
// (-21/2) / (3/7)
firstOperand = new Fraction(-21, 2);
secondOperand= new Fraction(3, 7);
result = firstOperand.divide(secondOperand);
System.out.print("8. The quotient of " + firstOperand +
" and " + secondOperand + " is \t" + result);
System.out.println("\n\tExpected result :\t\t-49/2\n");
// -21/2 + -7/-8
firstOperand = new Fraction(-21, 2);
secondOperand= new Fraction(-7, -8);
result = firstOperand.add(secondOperand);
System.out.print("9. The sum of " + firstOperand +
" and " + secondOperand + " is \t" + result);
System.out.println("\n\tExpected result :\t\t-77/8\n");
System.out.println("\n=========================================\n");
// 0/10, 5/(-15), (-22)/7
firstOperand = new Fraction(0, 10);
doubleResult = firstOperand.toDouble();
System.out.println("10. The double floating point value of " + firstOperand + " is \t" + doubleResult);
System.out.println("\tExpected result \t\t\t0.0\n");
firstOperand = new Fraction(1, -3);
doubleResult = firstOperand.toDouble();
System.out.println("11. The double floating point value of " + firstOperand + " is \t" + doubleResult);
System.out.println("\tExpected result \t\t\t-0.333333333...\n");
firstOperand = new Fraction(-15, -6);
doubleResult = firstOperand.toDouble();
System.out.println("12. The double floating point value of " + firstOperand + " is \t" + doubleResult);
System.out.println("\tExpected result \t\t\t\t2.5\n");
firstOperand = new Fraction(-21, 2);
System.out.println("First = " + firstOperand);
// equality check
System.out.println("13. check First equals First: ");
if (firstOperand.equals(firstOperand))
System.out.println("Identity of fractions OK");
else
System.out.println("ERROR in identity of fractions");
secondOperand = new Fraction(42, -4);
System.out.println("\nFirst = " + firstOperand);
System.out.println("Second = " + secondOperand);
System.out.println("14. check First equals Second: ");
if (firstOperand.equals(secondOperand))
System.out.println("Equality of fractions OK: equal");
else
System.out.println("ERROR in equality of fractions: equal");
secondOperand = new Fraction(-42, -4);
System.out.println("\nFirst = " + firstOperand);
System.out.println("Second = " + secondOperand);
System.out.println("15. check First equals Second: ");
if (firstOperand.equals(secondOperand))
System.out.println("ERROR in equality of fractions: not equal");
else
System.out.println("Equality of fractions OK: not equal");
// comparison check
// comparison check
secondOperand = new Fraction(42, -4);
Fraction first = (Fraction)firstOperand;
Fraction second = (Fraction)secondOperand;
System.out.println("\nFirst = " + first);
System.out.println("Second = " + second);
System.out.println("16. check First compareTo Second: ");
if (first.compareTo(second) == 0)
System.out.println("Fractions == operator OK");
else
System.out.println("ERROR in fractions == operator");
second = new Fraction(7, 8);
System.out.println("\nFirst = " + first);
System.out.println("Second = " + second);
System.out.println("17. check First compareTo Second: ");
if (first.compareTo(second) < 0)
System.out.println("Fractions < operator OK");
else
System.out.println("ERROR in fractions < operator");
System.out.println("\nFirst = " + first);
System.out.println("Second = " + second);
System.out.println("18. check Second compareTo First: ");
if (second.compareTo(first) > 0)
System.out.println("Fractions > operator OK");
else
System.out.println("ERROR in fractions > operator");
System.out.println("\n=========================================");
System.out.println("\n19. check FractionException: 1/0");
try {
Fraction a1 = new Fraction(1, 0);
System.out.println("Error! No FractionException");
}
catch ( FractionException fe )
{
System.err.printf( "Exception: %s\n", fe );
} // end catch
System.out.println("Expected result : FractionException!\n");
System.out.println("\n20. check FractionException: division");
try {
Fraction a2 = new Fraction();
Fraction a3 = new Fraction(1, 2);
a3.divide(a2);
System.out.println("Error! No FractionException");
}
catch ( FractionException fe )
{
System.err.printf( "Exception: %s\n", fe );
} // end catch
System.out.println("Expected result : FractionException!\n");
} // end main
} // end Fraction
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