C program to check even or odd using functions

Write a C program to input a number from user and check whether given number is even or odd using functions. How to check even or odd using functions in C programming. Write a function in C programming to check even or odd.

Example

Input

`Input any number: 10`

Output

`10 is even`

Declare function to find even odd

In my previous posts I have explained various ways to check even numbers. You can embed the logic to check even numbers using any of the following approaches in a function.

Let us define a function to check even or odd.

1. First give a meaningful name to our function, say `isEven()`.
2. Next, the function must accept one integer which is to be validated for even condition, say `isEven(int num)`.
3. Finally as per name, the function must return `true` if given integer is even otherwise `false`. However, C does not supports boolean values. In C programming, 0 is represented as `false` and 1 (any non-zero integer) as `true`. Hence, `isEven()` we must return an integer from function.

So the function declaration to check even number is `int isEven(int num);`

Program to check even or odd

``````/**
* C program to check even or odd using functions
*/

#include <stdio.h>

/**
* Function to check even or odd
* Returns 1 is num is even otherwise 0
*/
int isEven(int num)
{
return !(num & 1);
}

int main()
{
int num;

/* Input number from user */
printf("Enter any number: ");
scanf("%d", &num);

/* If isEven() function returns 0 then the number is even */
if(isEven(num))
{
printf("The number is even.");
}
else
{
printf("The number is odd.");
}

return 0;
}``````

In the above program I have used bitwise operator `&` to check even or odd numbers. However you can also use if else statement to check even or odd numbers.

Output

```Enter any number: 22
The number is even.```

Happy coding ðŸ˜‰