There are various ways to achieve this functionality. In this article, we’ll be using two ways :

1) Using if and else
2) Using ternary Operator

C program to Check Whether a Number is Even or Odd using if and else

Program : 

#include <stdio.h>
int main()
{
    int number ; 
    printf("Please enter a number : ");
    scanf("%d", &number);
    if(number % 2 == 0)
    {
        printf("%d is an even number.", number);
    }
    else{
        printf("%d is an odd number.", number);
    }
    return 0;
}

Output:

In the case of Even number input :

Please enter a number : 28                                                                               
28 is an even number.

In case of Odd number input :

Please enter a number : 7                                                                    
7 is an odd number.

Explanation:

In the above example, we have used if and else statement to check a number is even or odd. If number % 2, produces result as 0, then if block would be executed to print “even number message” on output screen, otherwise, else condition would be executed.

C program to Check Whether a Number is Even or Odd using ternary operator

Program:

#include<stdio.h>
#include<conio.h>
void main()
{
int number;
clrscr();
printf("\nPlease enter a number =");
scanf("%d",&number);
(number%2)==0?printf("\n %d is even",number):printf("\n %d is odd",number);
getch();
}

Output:

In case of even:

Please enter a number =20     
20 is even

In case of odd: 

Please enter a number =101     
101 is odd

In above code, we used same approach, but this time with the help of ternary operator to find a number is even or odd.

Approach :

1. Using Modulo Operator (%), we can find whether the input is divisible by 2 or not as it would give remainder as 1 otherwise 0
2.  If the remainder is zero, then it would be an even number, otherwise odd number