🔀⚡Beginner

Check Whether Number is Even or Odd

Determine if number is even or odd

A number is even if it is divisible by 2 (remainder = 0), otherwise it is odd. We use the modulus operator (%) to find the remainder.

📚 What You Will Learn

  • •Using the modulus operator (%)
  • •Simple if-else decision making
  • •Understanding divisibility

C Program to Check Even or Odd

even_odd.c
C
1#include <stdio.h>
2
3int main() {
4    int num;
5    
6    printf("Enter an integer: ");
7    scanf("%d", &num);
8    
9    // Check if remainder is 0 when divided by 2
10    if (num % 2 == 0) {
11        printf("%d is Even\n", num);
12    } else {
13        printf("%d is Odd\n", num);
14    }
15    
16    return 0;
17}
Output

Enter an integer: 7

7 is Odd

Understanding the Modulus Operator (%)

The % operator returns the remainder after division:

10 % 2
= 0
Even ✓
7 % 2
= 1
Odd
0 % 2
= 0
Even ✓
-4 % 2
= 0
Even ✓

Step-by-Step Execution:

1
Input

User enters 7

2
Calculate Remainder

7 % 2 = 1 (7 = 2×3 + 1)

3
Check Condition

1 == 0 is FALSE

4
Execute else

Prints "7 is Odd"

Alternative Methods

Using Bitwise AND Operator

main.c
C
1// Last bit of odd numbers is always 1
2if (num & 1)
3    printf("Odd");
4else
5    printf("Even");

Faster method! Checks the least significant bit (1 for odd, 0 for even).

Using Ternary Operator

main.c
C
1printf("%d is %s\n", num, (num % 2 == 0) ? "Even" : "Odd");

📝 Key Takeaways

✓% gives remainder after division
✓Even: num % 2 == 0
✓Odd: num % 2 != 0
✓Works for negative numbers too!
Previous
Check Positive, Negative, or Zero
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Check Whether Character is Vowel or Consonant

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