C program to check if number is even or odd

Let us use the if-else, ternary operator and switch case to explore different ways to check if a given number is even or odd.

Write a program to check if a number is even or odd using if-else

#include <stdio.h>

void main() {
    int num;

    printf("Enter number to check: ");
    scanf("%d", &num);

    if (num % 2 == 0)
        printf("%d is even", num);
    else
        printf("%d is odd", num);
}

We can further simplify the code as follows -

if (!(num % 2))
    printf("%d is even", num);
else
    printf("%d is odd", num);

Write a program to check if a number is even or odd using the ternary operator

#include <stdio.h>

void main() {
    int num;

    printf("Enter number to check: ");
    scanf("%d", &num);

    int isEven = num % 2 == 0 ?
        printf("%d is even", num) :  printf("%d is odd", num);
}

Write a program to check if a number is even or odd using switch

#include <stdio.h>

void main() {
    int num;

    printf("Enter number to check: ");
    scanf("%d", &num);

    switch (num % 2)
    {
        case 0:
          printf("%d is even", num);
          break;

        default:
          printf("%d is odd", num);
    }
}