Example: Check Prime Number
#include <iostream>
using namespace std;
bool check_prime(int);
int main() {
int n;
cout << "Enter a positive integer: ";
cin >> n;
if (check_prime(n))
cout << n << " is a prime number.";
else
cout << n << " is not a prime number.";
return 0;
}
bool check_prime(int n) {
bool is_prime = true;
// 0 and 1 are not prime numbers
if (n == 0 || n == 1) {
is_prime = false;
}
for (int i = 2; i <= n / 2; ++i) {
if (n % i == 0) {
is_prime = false;
break;
}
}
return is_prime;
}
Output
Enter a positive integer: 23 23 is a prime number.
In this example, the number entered by the user is passed to the check_prime() function.
This function returns true if the number passed to the function is a prime number, and returns false if the number passed is not a prime number.
Finally, the appropriate message is printed from the main() function.
To learn how the check_print() function works in detail, visit C++ Check Prime Example.