设计一个立方体类Box，他能计算并输出立方体的体积和表面积

#include <iostream>
using namespace std;
class Box
{
private:
    int a;
    int volume;
    int area;

public:
    Box(){};
    Box(int a)
    {
        this->a = a;
    }
    int getvolume()
    {
        volume = a * a * a;
        return volume;
    }
    int getarea()
    {
        area = 6 * a * a;
        return area;
    }
    void disp()
    {
        cout << "体积是 : " << getvolume() << endl;
        cout << "表面积是 : " << getarea() << endl;
    }
};
int main()
{
    int a;
    while (true)
    {
        cout << "请输入立方体边长：" << endl;
        if (cin >> a)
        {
            Box A(a);
            A.disp();
        }else{
            break;
        }
    }
    return 0;
}

照着这个来不就行了