Question
Write a class called RationalNumber that represents a fraction with an integer numerator and denominator.
A RationalNumber object should have the following methods:
public RationalNumber(int numerator, int denominator)
Constructs a new rational number to represent the ratio (numerator/denominator). The denominator cannot be 0,
so throw an IllegalArgumentException if 0 is passed.
public RationalNumber()
Constructs a new rational number to represent the ratio (0/1).
public int getDenominator()
Returns this rational number’s denominator value; for example, if the ratio is (3/5), returns 5.
public int getNumerator()
Returns this rational number’s numerator value; for example, if the ratio is (3/5), returns 3.
public String toString()
Returns a String representation of this rational number, such as "3/5". You may wish to omit denominators of 1,
returning "4" instead of "4/1".
An extra challenge would be to maintain your RationalNumber objects in reduced form, avoiding rational numbers such as 3/6 in favor of 1/2, or avoiding 2/–3 in favor of –2/3. Another possible extra feature would be methods to add, subtract, multiply, and divide two rational numbers.
Answer
PROGRAM CODE:
import java.math.BigInteger;
public class RationalNumber {
private int numerator;
private int denominator;
// Constructs a new rational number to represent the ratio (numerator/denominator)
public RationalNumber(int numerator, int denominator) {
if (denominator == 0) {
throw new IllegalArgumentException("Denominator cannot be 0.");
}
this.numerator = numerator;
this.denominator = denominator;
simplify();
}
// Constructs a new rational number to represent the ratio (0/1)
public RationalNumber() {
this(0, 1);
}
// Returns this rational number's denominator value
public int getDenominator() {
return denominator;
}
// Returns this rational number's numerator value
public int getNumerator() {
return numerator;
}
// Returns a String representation of this rational number
public String toString() {
if (denominator == 1) {
return Integer.toString(numerator);
}
return numerator + "/" + denominator;
}
// Simplifies the rational number to reduced form
private void simplify() {
int gcd = BigInteger.valueOf(numerator).gcd(BigInteger.valueOf(denominator)).intValue();
numerator /= gcd;
denominator /= gcd;
if (denominator < 0) {
numerator = -numerator;
denominator = -denominator;
}
}
}