C++设计源代码 类的实现

#include<iostream> using namespace std; class Box { public: Box(); Box(double length); void seta(double length); void getvolume(double length); void getarea(double length); void disp(); private: double a; double volume; double area; }; int main() { Box box; double length; cout << "Start to enter datas:\n"; box.seta(length); box.getvolume(length); box.getarea(length); box.disp(); return 0; } Box::Box():a(0),volume(0),area(0) { } Box::Box(double length) { if(length<0) { cout << "The data you enter for a length is illgle!\n"; exit(0); } a=length; } void Box::seta(double length) { cout << "Please enter the length of the box:"; cin >> length; a=length; } void Box::getvolume(double length) { volume=a*a*a; } void Box::getarea(double length) { area=6*a*a; } void Box::disp() { cout << "The length of the box you set is:" << a << endl; cout << "The volume of the box is:" << volume <<endl; cout << "The area of the box is:" << area <<endl; }