leap-year-checker

Returns true if the value is leap year. A simple JavaScript function to check if a given year is a leap year. This function includes error handling to validate the input.

Installation

npm install leap-year-checker

Usage

const { isLeapYear, getLeapYears, getNextLeapYear, getPreviousLeapYear } = require("leap-year-checker");

try {
  // Check if a year is a leap year
  console.log(isLeapYear(2024)); // Expected output: true
  console.log(isLeapYear(2023)); // Expected output: false

  // Find leap years within a range
  console.log(getLeapYears(2000, 2024)); // Expected output: [2000, 2004, 2008, 2012, 2016, 2020, 2024]

  // Get the next leap year after a given year
  console.log(getNextLeapYear(2023)); // Expected output: 2024

  // Get the previous leap year before a given year
  console.log(getPreviousLeapYear(2024)); // Expected output: 2020

  // Error handling for invalid inputs
  console.log(isLeapYear("2024")); // Throws error: Invalid input: year must be a positive integer.
  
} catch (error) {
  console.error("Error:", error.message);
}

Function Implementation

/**
 * Checks if a provided year is a leap year.
 * @param {number} year - The year to check
 * @throws {Error} - Throws an error if the input is not a valid positive integer
 * @returns {boolean} - Returns true if the year is a leap year, false otherwise
 */
function isLeapYear(year) {
  // Error handling: Check if input is a valid number and an integer
  if (typeof year !== 'number' || !Number.isInteger(year) || year <= 0) {
    throw new Error("Invalid input: year must be a positive integer.");
  }

  // Return true if it's a leap year, false otherwise
  return (year % 4 === 0 && year % 100 !== 0) || (year % 400 === 0);
}

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

This project is licensed under the MIT License.