检查用户输入的简单错误

Question

我在使用添加，减去和分割分数的方法时遇到了麻烦。我有乘法部分我只是在添加时遇到正确的输出问题。请帮我弄清楚我做错了什么我是Java新手，我还在学习。这是我到目前为止所得到的.`

private int numer;
private int denom;

public Fraction(int num, int den) {
    numer = num;
    denom = den;

simplify();
}
public int findGcd(int a, int b) {
    int temp;
    while (b != 0) {
        temp = b;
        b = a % b;
        a = temp;
    }
    return a;
}

void simplify() {
    int gcd = findGcd(numer, denom);
    numer /= gcd;
    denom /= gcd;
}
public int getNumer() {
    return numer;
}
public int getDenom() {
    return denom;
}

Fraction add(Fraction x) {
    Fraction answer;

    if (x.getDenom() == denom) {
        answer = new Fraction(x.getNumer() + numer, denom);
    } else {
        denom = this.getDenom() * x.getDenom();
        numer = this.getNumer() * x.getDenom() + x.getNumer()
                * this.getDenom();

        return new Fraction(numer, denom);

    }
    return answer;
}

Fraction subtract(Fraction x) {
    Fraction answer;

    if (x.getDenom() == denom) {
        answer = new Fraction(x.getNumer() - numer, denom);
    } else {
        denom = this.getDenom() * x.getDenom();
        numer = this.getNumer() * x.getDenom() - x.getNumer()
                * this.getDenom();
        answer = new Fraction(numer, denom);
    }
    return answer;
}

Fraction mult(Fraction x) {
    Fraction answer;

    denom = this.getDenom() * x.getDenom();
    numer = this.getNumer() * x.getNumer();
    answer = new Fraction(numer, denom);

    return answer;
}

Fraction div(Fraction x) {
    Fraction answer;

    denom = this.getDenom() * x.getNumer();
    numer = this.getNumer() * x.getDenom();
    answer = new Fraction(numer, denom);
    return answer;
}

当我输入2个分数时，它返回一个分数，但它不是正确的答案。我做错了什么？

更新

如果我使用小分数例如1/2和3/4它仍然给我错误的答案。对于添加，它打印出7/2，减法1/2和除法3/1。因此，我不认为必须做int或float号码。

Answer 1

在您的函数中，您将覆盖数字和denom的值。变化：

denom = this.getDenom() * x.getDenom(); 
numer = this.getNumer() * x.getDenom() - x.getNumer() 
            * this.getDenom(); 
answer = new Fraction(numer, denom); 

到

int newdenom = this.getDenom() * x.getDenom(); 
int newnumer = this.getNumer() * x.getDenom() - x.getNumer() 
            * this.getDenom(); 
answer = new Fraction(newnumer, newdenom);