Leap Year Checker in C++

This document provides a C++ program that checks whether a given year is a leap year. It includes a detailed explanation of the program structure and comments for clarity.

Program Code

#include <iostream>

using namespace std;

/**
 * @brief Checks if a given year is a leap year.
 * @param year The year to be checked.
 * @return True if the year is a leap year, false otherwise.
 */
bool isLeapYear(int year) {
    // Leap year is divisible by 4
    if (year % 4 == 0) {
        // If the year is a century year, it must be divisible by 400
        if (year % 100 == 0) {
            // Century year divisible by 400 is a leap year
            if (year % 400 == 0) {
                return true;
            } else {
                return false;
            }
        } else {
            // Non-century year divisible by 4 is a leap year
            return true;
        }
    } else {
        // Year not divisible by 4 is not a leap year
        return false;
    }
}

int main() {
    int year;

    cout << "Enter a year: ";
    cin >> year;

    if (isLeapYear(year)) {
        cout << year << " is a leap year." << endl;
    } else {
        cout << year << " is not a leap year." << endl;
    }

    return 0;
}
    

Program Explanation

The program is structured as follows:

1. Include Directives:The program includes the <iostream> header file, which is required for input and output operations.
2. Using Namespace:The using namespace std; directive is used to avoid prefixing standard library names with std::.
3. Function Definition (isLeapYear):The isLeapYear function takes an integer year as a parameter and returns a boolean value indicating whether the year is a leap year.
   • First, the function checks if the year is divisible by 4.
   • If the year is divisible by 4, it checks if it is a century year (divisible by 100).
   • If it is a century year, it further checks if it is divisible by 400.
   • The year is considered a leap year if it meets the conditions outlined above; otherwise, it is not.
4. Main Function:The main function is the entry point of the program.
   • It prompts the user to enter a year.
   • The isLeapYear function is called with the entered year, and the result is used to display whether the year is a leap year or not.

Documentation

The program is documented with comments to explain the purpose of each part of the code:

• Comments are added to the isLeapYear function to describe the logic behind checking leap years.
• Inline comments in the main function explain user interactions and the flow of the program.