Example: Functional Divisibility Checks in C

// Functional Divisibility Checks
#include <stdio.h>
#include <stdbool.h> // For using bool type

// Function to check if a number is even
bool isEven(int num) {
    return (num % 2 == 0);
}

// Function to check if a number is odd
bool isOdd(int num) {
    return (num % 2 != 0);
}

// Function to check if a number is divisible by 3
bool isDivisibleBy3(int num) {
    return (num % 3 == 0);
}

int main() {
    int number;

    // Step 1: Prompt user for input
    printf("Enter an integer: ");
    scanf("%d", &number);

    // Step 2: Use functions to determine properties
    if (isEven(number)) {
        printf("%d is an even number.\n", number);
    } else {
        printf("%d is an odd number.\n", number);
    }

    if (isDivisibleBy3(number)) {
        printf("%d is divisible by 3.\n", number);
    } else {
        printf("%d is not divisible by 3.\n", number);
    }

    // Step 3: Combine functional checks
    if (isEven(number) && isDivisibleBy3(number)) {
        printf("%d is even and divisible by 3.\n", number);
    } else if (isOdd(number) && isDivisibleBy3(number)) {
        printf("%d is odd and divisible by 3.\n", number);
    } else if (isEven(number) && !isDivisibleBy3(number)) {
        printf("%d is even but not divisible by 3.\n", number);
    } else { // isOdd(number) && !isDivisibleBy3(number)
        printf("%d is odd and not divisible by 3.\n", number);
    }

    return 0;
}