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()}