这是一个考题，大家帮忙看下，谢谢！

Question

建立类box,box的构造函数被传递了3个double值，每一个double值表示盒子的一条边长。用BOX类计算立方的体积，并存储在一个double变量中，在BOX类中包含一个成员函数 VOl( ),用来显示每个对象的体积

Answer 1

class Box
{
double a,b,c;
public:
Box(double,double,double);
Void VOI();
};
Date::Box(double x,double y,double z)
{
a=x;
b=y;
c=z;
}
void Box::VOI()
{
double v=a*b*c;
printf("%f",v);
}

Answer 2

#include <stdio.h>
class box
{
private:
double m_a,m_b,m_c;
public:
box(double a,double b,double c):m_a(a),m_b(b),m_c(c){}
void vol()
{
double d = m_a * m_b * m_c;
printf("%g\n",d);
}
};

int main()
{
box b(1.1,2.2,3.3);
b.vol();
return 0;
}

Answer 3

class box
{
private：
double m_x;double m_y;double m_z;double m_vol;
public:
box(double m_x,double m_y,double m_z){
this->m_x=m_x;this->m_y=m_y;
this->m_z=m_z;
this->m_vol=m_x*m_y*m_z;}
~box();
void vol()
}