I have a class Calculator which aggregates instances of a class Fraction as its attributes.
Class Fraction has attributes num for numerator and denom for denominator.
Here is an abstract of the code with 'multiply' and 'simplify' (to get a fraction in its lowest terms) methods.
public class Calculator {
private Fraction f1 = new Fraction(4, 9);
private Fraction f2 = new Fraction(3, 8);
public void multiply() throws Exception {
int num = f1.getNum() * f2.getNum();
int denom = f1.getDenom() * f2.getDenom();
Fraction f = new Fraction(num, denom);
simplify(f);
System.out.print(f);
}
private void simplify(Fraction f) throws Exception {
int num = f.getNum();
int denom = f.getDenom();
for (int i = num; i > 0; i--) {
if ((num % i == 0) && (denom % i == 0)) {
num = num / i;
denom = denom / i;
break;
}
}
}
However, I get 12/72 as a result of multiplication while I should get 1/6. How can I change the code so that 'simplify' method works when invoked in 'multiply'?
CodePudding user response:
As Edwin commented you want algorithm for greatest common divisor. However to answer your question, you got unexpected result because the newly computed variables num
and denom
at the line with num = num / i
are not stored back into Fraction f
.
Either (worse option) call f.setNum(num); f.setDenom(denom)
or (better) change Fraction
to immutable class and return new Fraction
from simplify
method.