# Even or Odd program in C++

In this example, you will write the c++ program to check whether the number entered by the user is even or odd.

When the number is completely divisible by 2 and the remainder is zero then the number is even. for example, 2, 4, 6, 8, 10, 12,  14, 16, 18, 20, etc are even number.

when a number is not divisible by 2 and has some remainder then the number is called an odd number. for example, 1, 3, 5, 7, 9, 11, 13, etc are odd number.

## program to check even or odd using if else

``````
#include <iostream>
using namespace std;

int main() {
int num;

cout << "Enter the number: ";
/* take input from user */
cin >> num;

if ( num % 2 == 0)
cout << num << " is even";
else
cout << num << " is odd";

return 0;
}

``````
output
```Enter the number: 12
12 is even```
```Enter the number: 11
11 is odd```

In the program, we have taken the integer number from the user and stored it in the variable `num`.

when if-statement is evaluated true i.e (`num % 2`) then print an even number and if not true, else part will get executed and print not even.

## Check even or odd using ternary operator

In this program, we have used a ternary operator for finding even or odd instead of if-else.

``````
#include <iostream>
using namespace std;

int main() {
int num;

cout << "Enter the number: ";
cin >> num;

// ternary operator
(num % 2 == 0) ? cout << num << " is even" :  cout << num << " is odd";

return 0;
}
``````
output
```Enter the number: 4
4 is even```

## Check even odd using class

In this example, we have used class for determining even or odd

``````
#include<iostream>
using namespace std;

class StudyFame {
private:
int num;
public:
void getData();
void EvenOdd();
};
void StudyFame::getData() {
cout << "Enter the number: ";
cin >> num;
};
void StudyFame::EvenOdd() {
if ( num % 2 == 0)
cout << num << " is even";
else
cout << num << " is odd";
};
int main() {
StudyFame s;
s.getData();
s.EvenOdd();
return 0;
}
``````
output
```Enter the number: 10
10 is even```

Time Complexity of all above program is: O(1)