Check if a Year is a Leap Year - C Program

This blog post demonstrates a C program to determine whether a given year is a leap year or not. A leap year is divisible by 4, but if it is divisible by 100, it must also be divisible by 400.

Program Code

#include <stdio.h>

// Function to check if a year is a leap year
int isLeapYear(int year) {
    if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
        return 1; // Leap year
    } else {
        return 0; // Not a leap year
    }
}

int main() {
    int year;

    // Prompt user for input
    printf("Enter a year: ");
    scanf("%d", &year);

    // Check if the year is a leap year
    if (isLeapYear(year)) {
        printf("%d is a leap year.\n", year);
    } else {
        printf("%d is not a leap year.\n", year);
    }

    return 0;
}

Explanation

This program performs the following steps:

1. Include the Standard I/O Library: The program includes the <stdio.h> library for input and output operations.
2. Define Leap Year Function: The isLeapYear() function checks if a year is a leap year using the rules: divisible by 4 but not by 100, unless divisible by 400.
3. Read User Input: The program reads an integer year from the user.
4. Check Leap Year: It uses the isLeapYear() function to determine if the year is a leap year and prints the result.

This program effectively demonstrates basic condition checks and modular programming in C.