一个控制台程序，要求构建一个BOX盒子类，该类含有3个数据成员，分别表示盒子的3条边长；含有一个成员函数，用来计算盒子的体积并输出。演示输出。-A console program, to build a BOX box class, the class contains three data members, respectively of the box side length of 3　contains a member function, and used to calculate the volume and output of the box. The demo output.