My problem is how do i make this work

Question

import java.util.Scanner;

public class Fraction
{
private int numerator;
private int denominator;
    private int product;
    private int sum;

public Fraction(int num, int denom)
{
 this.numerator=num;
 this.denominator=denom;

 if (this.denominator == 0){

 System.out.println("can not divide by zero");
 }// end if
}// end fraction


  public void print()
  {
       System.out.println(this.numerator + "/" + this.denominator);
  }

public void printAsDouble()
{
 System.out.println((double) this.numerator / this.denominator);
}

public mulitply(Fraction)
{
 Fraction(x).product = ((( Fraction(c).numerator * Fraction(d).denominator) + (Fraction(d).numerator * Fraction(c).denominator)) / (Fraction(c).denominator * Fraction(d).denominator));
}
}// end class Fractiont

I keep getting the same errors expected and invalide method declaration

Ok i have a new fraction in my main class called x and that is where i was calling the fraction X from. and what does it mean that it needs to return something?

Answer 1

multiply has no return type defined. Fraction has no one-argument constructor.

Answer 2

This is not legal Java code:

Fraction(x).product =  ((( Fraction(c).numerator * Fraction(d).denominator) + (Fraction(d).numerator * Fraction(c).denominator)) / (Fraction(c).denominator * Fraction(d).denominator));

Objects are created using the "new" keyword:

new Fraction(x).product = ...

Also, you need to specify argument names and return values in prototypes:

public void mulitply(Fraction f)
{
....

Answer 3

Your multiply function is totally messed up. Could you tell us what you want to do?

Here are two examples of how a multiply function could look like, but you either have to set the field numerator and denominator public or implement getter methods:

public void multiply( Fraction b ) {
 this.numerator = this.numerator * b.numerator;
 this.denominator = this.denominator * b.denominator;
}

public static Fraction multiply( Fraction a, Fraction b ) {
 return new Fraction( a.numerator*b.numerator, a.denominator*b.denominator );
}

In your main function you could call this then like this: (See the difference between the static and "normal" method)

Fraction x = new Fraction( 1, 2 );
Fraction m = new Fraction( 1, 3 );

Fraction result = Fraction.multiply( x, m );
result.print();  // 1/6

x.print();   // 1/2
x.multiply( m );
x.print();   // 1/6

If you want to chain calls, do it like this:

public Fraction multiply( Fraction b ) {
 this.numerator = this.numerator * b.numerator;
 this.denominator = this.denominator * b.denominator;
 return this;
}

Then you can do things like

Fraction x = new Fraction(1,2).multiply( new Fraction(1,3) ).multiply( new Fraction(2,5) );