标准C++命名空间的使用

shape.h

/*
    Circle
*/

namespace G_Shape
{
     class Circle
    {
     public:
         double calculate_perimeter( double radius);
         double calculate_area( double radius);
     private:
         double radius;
    };

     /*
        Rectangle
     */
     class Rectangle
    {
     public:
         double calculate_perimeter( double width,  double height);
         double calculate_area( double width,  double height);
     private:
         double width;
         double height;
    };
}

 

shape.cpp

#include  " shape.h "

using  namespace G_Shape;

#define PI 3.14159

/*
    Circle
*/

double Circle::calculate_perimeter( double radius)
{
     return  2 * PI * radius;
}

double Circle::calculate_area( double radius)
{
     return PI * radius * radius;
}


/*
    Rectangle
*/

double Rectangle::calculate_perimeter( double width,  double height)
{
     return  2 * (width + height);
}

double Rectangle::calculate_area( double width,  double height)
{
     return width * height;
}

 

mainframe.cpp

#include <iostream>
#include  " draw/shape.h "

using  namespace std;
using  namespace G_Shape;

int main()
{
     // Circle    
     double radius;

    cout<<  " Please input radius of the circle: ";
    cin>>radius;

    Circle c;
    cout <<  " Circle Perimeter:  " << c.calculate_perimeter(radius) <<endl;
    cout <<  " Circle Area:  " << c.calculate_area(radius) <<endl;

     // Rectangle
     double width, height;

    cout<<  " Please input width of the rectangle: ";
    cin>>width;
    cout<<  " Please input height of the rectangle: ";
    cin>>height;

    Rectangle r;
    cout <<  " Rectangle Perimeter:  " << r.calculate_perimeter(width, height) <<endl;
    cout <<  " Rectangle Area:  " << r.calculate_area(width, height) <<endl;
    
     return  0;
}

 

运行结果:

david@ubuntu:~/MyProject/Hades$ ./mainframe.exe
Please input radius of the circle:5
Circle Perimeter: 31.4159
Circle Area: 78.5397
Please input width of the rectangle:4
Please input height of the rectangle:5
Rectangle Perimeter: 18
Rectangle Area: 20

 

 

 

转载于:https://www.cnblogs.com/davidgu/archive/2012/06/28/2567801.html