你想要输出吗？
#include<iostream>
using namespace std;
const float PI=3.14f;
class Ar
{private:
float m,r;
public:
Ar()
{r=3.6f;}
Ar(float rr)
{rr=3.6f;r=rr;}
~Ar()
{
delete float rr;
}
float ar_r();
};
float Ar::ar_r( )
{
float a=r*r*PI;
printf("r:%f.area:%f\n",r,a);
return a;
}
void main()
{ float m;
Ar ar1( );
Ar ar2=3.7f;
m=ar2.ar_r( );
}
