C++warning C4552: “*”: 运算符不起任何作用；应输入带副作用的运算符

Question

#include
#include
#include
using namespace std;
int main()
{
double r,h,c,area1,area2,v1,v2,pi;
#define pi 3.1415;
cout<<"请输入半径:"< cin>>r>>h;
c=2*pi*r;
area1=pi*r;
area2=4*pi*r*r;
v1=4/3*pi*r*r*r;
v2=pi*r*r*h;
cout<<"圆周长"<<"c="<<c<<"圆面积"<<"area1="<<area1<<"圆球表面积"<<"area2="<<area2<<"圆球体积"<<"v1="<<v1<<"圆柱体积"<<"v2="<<v2<<endl;
return 0;
}

Answer 1

#define pi 3.1415; 注意define 后没有; define 应该将pi 代替为3.1415;了，多了个;good question.