p270 默认参数的构造函数.cpp

谭浩强 《C++ 程序设计》第三版的部分课后练习题源码

#include<iostream>
using namespace std;
class Box
{
      private:
              float length;
              float width;
              float height;
      public:
             Box(float a=10,float b=10,float c=10);
             void set_value();
             void cubage();
            
};

void Box::set_value()
{
      cout<<"please input the length width and height: ";
      cin>>length>>width>>height;
      
}

void Box::cubage()
{
      float cube;
      cube=length*width*height;
      cout<<"the cubage of the cube is "<<cube<<endl;
     
     
}

Box::Box(float a,float b,float c):length(a),width(b),height(c){}


int main()
{   
     Box cube1(12);//,
    // cube1.set_value();
     cube1.cubage();
    // cube2.set_value();
     Box cube2(10,14);
     cube2.cubage();
     Box cube3(10,14,15);
     cube3.cubage();
     system("pause");
     return 0;
    
    
    
    }