C Program To Check Whether a Number is Even or Odd

In this post, we will write a program to check whether a Number is Even or Odd.

A number which is exactly divisible by 2 is called an Even Number. For Example – 2, 32, 256 etc.

A number which is not exactly divisible by 2 is called an Odd Number. For Example – 3, 17, 247 etc.

We will be using different methods to check whether the number entered by the user is Even or Odd.

So, Without Further Ado, let’s begin the tutorial.

C Program To Check Whether a Number is Even or Odd

// C Program To Check Whether a Number is Even or Odd
#include <stdio.h>
int main(){
    int num;
    
    // Asking for Input
    printf("Enter the Number: ");
    scanf("%d", &num);
    
    // Even if num is divisible by 2
    if (num % 2 == 0)
        printf("%d is an Even Number", num);
    else
        printf("%d is an Odd Number", num);
    
    return 0;
}

Output

Enter the Number: 13
13 is an Odd Number

How Does This Program Work ?

 int num;

Here, in this program we have declared an int variable num.

    // Asking for Input
    printf("Enter the Number: ");
    scanf("%d", &num);

Then, the user is asked to input the input. The integer entered by the user is stored in the num variable.

    // Even if num is divisible by 2
    if (num % 2 == 0)
        printf("%d is an Even Number", num);
    else
        printf("%d is an Odd Number", num);

If the num is perfectly divisible by 2 ,the expression evaluates to True. This means the number is Even.

And If the num is not perfectly divisible by 2, then in this case the expression evaluates to 0 (False). This states the number is Odd.

Some used terms are as follow:

#include <stdio.h> – In the first line we have used #include, it is a preprocessor command that tells the compiler to include the contents of the stdio.h(standard input and output) file in the program.

The stdio.h is a file which contains input and output functions like scanf() and printf() to take input and display output respectively. 

Int main() – Here main() is the function name and int is the return type of this function. The Execution of any Programming written in C language begins with main() function. 

scanf() – scanf() function is used to take input from the user. 

printf() – printf() function is used to display and print the string under the quotation to the screen.

% – % (Modulus Operator) is used for division.

If. . . else – An if statement can be followed by an optional else statement, which executes when the Boolean expression is false. If Statement executes when the Boolean expression is True.

// – Used for Commenting in C

Using Bitwise Operator

// C Program To Check Whether a Number is Even or Odd
#include <stdio.h>
int main(){
    int num;
    
    // Asking for Input
    printf("Enter the Number: ");
    scanf("%d", &num);
    
    if (num & 1)
        printf("%d is an Odd Number", num);
    else 
        printf("%d is an Even Number", num);
        
    return 0;    
}

Output

Enter the Number: 86
86 is an Even Number

    if (num & 1)
        printf("%d is an Odd Number", num);
    else 
        printf("%d is an Even Number", num);

num & 1 is a Bitwise AND operation of the num variable and 1 literal.

Using Ternary Operator

// C Program To Check Whether a Number is Even or Odd
#include <stdio.h>
int main(){
    int num;
    
    // Asking for Input
    printf("Enter the Number: ");
    scanf("%d", &num);
    
    (num % 2 == 0) ? printf("%d is an Even Number", num) : printf("%d is an Odd Number", num);
    
    return 0;
}

Output

Enter the Number: 18
18 is an Even Number

(num % 2 == 0) ? printf("%d is an Even Number", num) : printf("%d is an Odd Number", num);

In this program, we have used ? : (ternary operator) instead of the if. . . else statement.

Conclusion

I hope after reading this post, you understand how to check whether a number is Even or Odd in C Programming language. 

If you have any doubt regarding the topic, feel free to contact us in the Comment Section. We will be delighted to help you.