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.

## Example 1: Check Whether Number is Even or Odd using if else

```
#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.

## Example 2: Check Whether Number is Even or Odd using ternary operators

```
#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;
}
```