31 lines
553 B
C++
31 lines
553 B
C++
|
// 函数的默认参数
|
||
|
|
|
||
|
|
#include <iostream>
|
||
|
|
|
||
|
|
using namespace std;
|
||
|
|
|
||
|
|
bool isSs(int n = 10) // 判断 n 是否为质数
|
||
|
|
{
|
||
|
|
int i = 2;
|
||
|
|
for (; i < n / 2; i++)
|
||
|
|
{
|
||
|
|
if (n % i == 0)
|
||
|
|
return false; // 0 为假
|
||
|
|
}
|
||
|
|
return true; // 非 0 为真
|
||
|
|
}
|
||
|
|
|
||
|
|
double area(double r = 1.0) // 求面积
|
||
|
|
{
|
||
|
|
return 3.14 * r * r;
|
||
|
|
}
|
||
|
|
|
||
|
|
int main()
|
||
|
|
{
|
||
|
|
cout << "isSS(7) is " << isSs(7) << endl;
|
||
|
|
cout << "isSS() is " << isSs() << endl;
|
||
|
|
cout << "area() is " << area() << endl;
|
||
|
|
cout << "area(2) is " << area(2) << endl;
|
||
|
|
return 0;
|
||
|
|
}
|