#include "iostream.h"
#include "stdlib.h"
#include "math.h"
void star(int a);
int main()
{
    int n;
    cout<<"请输入星号的个数：";
    cin>>n;
    cout<<star(n)<<endl;
    return 0;
}
void star(int a)
{
    
    for(int i=0;i<a;i++)
    {
        cout<<'*';
    }
}


error C2679: binary '<<' :no operator defined which takes a right-hand operand of type 'void' (or there is no acceptable conversion)

#include "stdlib.h"不是已经调用void了？

怪我~看书不仔细~