circle.cpp

来自「谭浩强C程序设计习题答案」· C++ 代码 · 共 19 行

//习题12.1中的circle.cpp文件
//CIRCLE.CPP
//#include <iostream.h>
Circle::Circle(float a,float b,float r):Point(a,b),radius(r){}

void Circle::setRadius(float r)
{radius=r;}

float Circle::getRadius() const {return radius;}

float Circle::area() const
{return 3.14159*radius*radius;}

ostream &operator<<(ostream &output,const Circle &c)
{output<<"Center=["<<c.x<<","<<c.y<<"], r="<<c.radius<<", area="<<c.area()<<endl;
 return output;
}