从float转换为int

Question

#include <iostream>
using namespace std;

int main(){
 float const PI = 3.1415926;

int radius = 4;
int peri = 0;
int area = 0;

peri =(float) (PI * 2)* radius;
area = (float) PI * (radius * radius);

cout << "Radius is " << radius << endl;
cout << "Perimeter is " << peri << endl;
cout << "Area is " << area << endl;

return 0;
};

peri和area不会转换为float并始终收到警告“从float转换为int”似乎是个问题..

Answer 1

如果你真的想要将peri和area截断为整数，你应该明确地这样做：

peri=static_cast<int>(2*PI*radius);
area=static_cast<int>(PI*radius*radius);

否则，您将收到警告，对于阅读您的代码的任何人来说，这似乎都是错误的。