COMP 170    -    PROGRAM VII  (Fraction Calculator)

Design, test, and run a project, FractionCalculator, which contains a class, Fraction,  that defines Fraction objects and several instance methods corresponding to Fraction arithmetic operations (addition, multiplication, division, reduction to lowest terms).   (For the sake of simplicity, you may assume that the fractions are all non-negative numbers.)  You will also design a class (or client), FractionCalculator, containing the main method which asks the user for input and performs standard arithmetic operations upon the fractions, and then prints the results.
 

Sample dialogue:

Welcome to Antoine Roquentin's fraction calculator.

Choose from the following menu (type the character of your choice):
A:  to add two fractions.
M:  to multiply two fractions.
D:  to divide two fractions.
R:  to reduce a fraction to lowest terms.
X:  to terminate this session.
A
Type your first fraction (Numerator on first line;  Denominator on next line):
13
2
Type your second fraction:
6
9
Thank you.  The sum of 13/2 and 6/9 is 43/6.

Choose from the following menu (type the character of your choice):
A:  to add two fractions.
M:  to multiply two fractions.
D:  to divide two fractions.
R:  to reduce a fraction to lowest terms.
X:  to terminate this session.
R
Type your fraction (Numerator on first line;  Denominator on next line):
400
1200
Thank you. The reduced form of 400/1200 is 1/3.

Choose from the following menu (type the character of your choice):
A:  to add two fractions.
M:  to multiply two fractions.
D:  to divide two fractions.
R:  to reduce a fraction to lowest terms.
X:  to terminate this session.
M
Type your first fraction (Numerator on first line;  Denominator on next line):
8
27
Type your second fraction:
3
4
Thank you.  The product of 8/27 and 3/4 is 2/9.

Choose from the following menu (type the character of your choice):
A:  to add two fractions.
M:  to multiply two fractions.
D:  to divide two fractions.
R:  to reduce a fraction to lowest terms.
X:  to terminate this session.
X
Thank you for using the Fraction Calculator!  Type any character to end session.

Notes:

• A robust program will alert the user to possible division by 0.
• To design your reduce instance method (for reducing a fraction to lowest terms), you should use the Euclidean algorithm.
• Always express your answer in lowest terms.  For example, it is not acceptable to write: The sum of 4/2 and 8/4 is 16/4.  Instead, write:  The sum of 4/2 and 8/4 is 4/1. (Notice that the user can input fractions that are NOT in reduced form, yet the calculator always expresses an answer in lowest terms.)  For extra credit you may wish to improve the appearance of output, so that 4/1 is written simply as 4.
• A well-written program will reduce fractions internally before the actual arithmetic is performed.  For example, to evaluate  (100000000/100000000)*(300000000/100) the reduction should occur prior to multiplication.  Otherwise overflow errors will occur!
• Use static methods appropriately.  For example, gcd(int, int) and displayMenu() should be static methods. The former should reside in the Fraction class;  the latter should reside in the FractionCalculator class.
• For additional extra credit, modify your Fraction class so that an object includes three fields:  a "sign" (char type) as well as a numerator (int) and denominator (int).  Define (and test) a subtraction method in the Fraction class.

Electronic submission of the files:   FractionCalculator.java and Fraction.java.
 
 

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