JAVA：我的代码中没有错误，但我没有得到正确的答案

Question

以下是可能包含问题的代码部分。这是我的班级。

private int GCD(int Num, int Denom)
    {
        int gcd;
        gcd = Num % Denom;
        if(gcd == 0)
            return Denom;
        else
        {
            return GCD(Denom, gcd);
        }
    }

    public Fractions add(Fractions frac)
    {
        Fractions newFrac = new Fractions();
        this.Num = this.Num * frac.Denom;
        this.Denom = this.Denom * frac.Denom;
        frac.Num = frac.Num * this.Denom;
        frac.Denom = frac.Denom * this.Denom;
        frac.Denom = this.Denom;
        newFrac.Denom = frac.Denom;
        newFrac.Num = this.Num + frac.Num;
        Denom = GCD(newFrac.Num, newFrac.Denom);
        if (Denom == 0)
            return newFrac;
        else
        {
            newFrac.Num = newFrac.Num / Denom;
            newFrac.Denom = newFrac.Denom / Denom;
            return newFrac;
        }
    }

这是我为它写的小型演示代码。请帮我找到问题所在。

public class FractionsDemo
{
    public static void main(String [] args)
    {
        Fractions frac1 = new Fractions();
        Fractions frac2 = new Fractions();
        Fractions frac3 = new Fractions();

        frac1.read();
        frac2.read();

        System.out.println("The first fraction is " + frac1.Num + "/" + frac1.Denom);
        System.out.println("The second fraction is " + frac2.Num +"/" + frac2.Denom);


        frac3 = frac1.add(frac2);
        System.out.println("adding the first and second results in " + frac3.Num + "/" + frac3.Denom );



    }

}

正如我在标题中提到的，我的代码不会显示任何错误。问题是一个逻辑问题。非常感谢您的帮助。另外，请尝试解释您的解决方案的原因。提前致谢。

Answer 1

问题出在这里

    this.Denom = this.Denom * frac.Denom;
    frac.Num = frac.Num * this.Denom;

您在设置frac.Num之前设置此.Denom，您必须将订单切换到

    frac.Num = frac.Num * this.Denom;
    this.Denom = this.Denom * frac.Denom;