#include<iostream> using namespace std; class circle { public: double r; double pi=3.1415926; // double area; double area=pi*r*r; //没写成员函数 /*double Area() { area=pi*r*r; }*/ }; int main() { circle c1; cout<<"please input your r"<<endl; cin>>c1.r; cout<<c1.area<<endl;//乱码 //cout<<c1.Area()<<endl return 0; }
解释正确