Check Whether Number is Even or Odd

Integers which are perfectly divisible by 2 are called even numbers. And those integers which are not perfectly divisible by 2 are not known as odd number. To check whether an integer is even or odd, the remainder is calculated when it is divided by 2 using modulus operator %. If remainder is zero, that integer is even if not that integer is odd.

#include <iostream>
using namespace std;

int main() {
    int n;
    cout << "Enter an integer: ";
    cin >> n;
    if ( n%2 == 0) {
        cout << n << " is even.";
    }
    else {
        cout << n << " is odd.";

    }
    return 0;
}

Output

Enter an integer: 23
23 is odd.

In this program, if..else statement is used to check whether n%2 == 0 is true or not. If this expression is true, n is even if not n is odd.

You can also use ternary operators ?: instead of if..else statement. Ternary operator is short hand notation of if...else statement.

#include <iostream>
using namespace std;

int main() {
    int n;
    cout << "Enter an integer: ";
    cin >> n;
    
    (n%2 == 0) ? cout << n << " is even." :  cout << n << " is odd.";
    
    return 0;
}