写出一段c++代码,用类函数，可以满足将分数（含分子分母）进行加减乘除运算，并且允许键盘输入分数（含分子分母），且输出最后结果。

当然，这里是一个简单的C++程序示例，它定义了一个分数类Fraction，并实现了加、减、乘、除的操作。用户可以通过输入分子和分母来进行操作，并显示结果。

#include <iostream>
using namespace std;

class Fraction {
private:
    int numerator;
    int denominator;

public:
    // 构造函数
    Fraction(int num = 0, int den = 1) : numerator(num), denominator(den) {}

    // 检查分母是否为0
    bool isZeroDenominator() const {
        return denominator == 0;
    }

    // 加法
    Fraction add(const Fraction& other) const {
        int newNumerator = numerator * other.denominator + other.numerator * denominator;
        int newDenominator = denominator * other.denominator;
        return Fraction(newNumerator, newDenominator);
    }

    // 减法
    Fraction subtract(const Fraction& other) const {
        int newNumerator = numerator * other.denominator - other.numerator * denominator;
        return Fraction(newNumerator, denominator);
    }

    // 乘法
    Fraction multiply(const Fraction& other) const {
        return Fraction(numerator * other.numerator, denominator * other.denominator);
    }

    // 除法，需要检查除数是否为0
    Fraction divide(const Fraction& other) const {
        if (other.isZeroDenominator()) {
            throw "Cannot divide by zero!";
        }
        return Fraction(numerator * other.denominator, denominator * other.numerator);
    }

    // 输出分数
    void print() const {
        cout << numerator << "/" << denominator << endl;
    }
};

int main() {
    Fraction f1, f2;
    
    cout << "Enter the first fraction (numerator/denominator): ";
    cin >> f1.numerator >> f1.denominator;
    cout << "Enter the second fraction (numerator/denominator): ";
    cin >> f2.numerator >> f2.denominator;
    
    Fraction result;
    cout << "Choose an operation (+, -, *, /): ";
    char op;
    cin >> op;

    switch(op) {
        case '+':
            result = f1.add(f2);
            break;
        case '-':
            result = f1.subtract(f2);
            break;
        case '*':
            result = f1.multiply(f2);
            break;
        case '/':
            try {
                result = f1.divide(f2);
            } catch (const char* msg) {
                cerr << msg << endl;
                return 1; // 错误处理
            }
            break;
        default:
            cerr << "Invalid operation!" << endl;
            return 1; // 非法操作
    }

    result.print();
    cout << "Result: " << result.print() << endl;

    return 0;
}