C++编译头文件和多个cpp

头文件(shape.h):

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

shape.cpp:

#include "shape.h"

#define PI 3.14159

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

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

主程序

test.cpp

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

using namespace std;

int main()
{
int 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;
return 0;
}

ubuntu下编译命令:

g++ -o test.exe shape.cpp test.cpp

运行结果:

Please input radius of the circle:5
Circle Perimeter: 31.4159
Circle Area: 78.5397

如果我门把头文件放在某个draw目录下

在主程序include的路径需要修改一下

#include "draw/shape.h"

编译指令:

g++ -o test.exe draw/*.cpp test.cpp