This C++ program to check whether the given number is even or odd.

even numbers are perfectly *divisible by 2*. In this example program, *if else* statement is used to check whether a number entered by the user is even or odd.

```
#include <iostream>
using namespace std;
int main() {
int a;
cout << "Enter the number: "; cin >> a;
/* logic */
if (a % 2 == 0) {
cout << "The given number is EVEN" << endl;
} else {
cout << "The given number is ODD" << endl;
}
return 0;
}
```

Program Output:

Enter the number: 8 The given number is EVEN

Explanation:

**Example 1: If entered number is an even number.**

Let value of 'a' entered is 8

if(a%2==0) then a is an even number, else odd.

i.e. if(8%2==0) then 8 is an even number, else odd.

To check whether 8 is even or odd, we need to calculate (8%2).

/* % (modulus) implies remainder value. */

/* Therefore if the remainder obtained when 8 is divided by 2 is 0, then 8 is even. */

8%2==0 is true

Thus 8 is an even number.

**Example 2: If entered number is an odd number.**

Let value of 'a' entered is 7

if(a%2==0) then a is an even number, else odd.

i.e. if(7%2==0) then 4 is an even number, else odd.

To check whether 7 is even or odd, we need to calculate (7%2).

7%2==0 is false /* 7%2==1 condition fails and else part is executed */

Thus 7 is an odd number.