odin-javascript-exercises/06_leapYears/solution/leapYears-solution.js

const leapYears = function (year) {
  const isYearDivisibleByFour = year % 4 === 0;
  const isCentury = year % 100 === 0;
  const isYearDivisibleByFourHundred = year % 400 === 0;

  if (
    isYearDivisibleByFour &&
    (!isCentury || isYearDivisibleByFourHundred)
  ) {
    return true;
  } else {
    return false;
  }
};

module.exports = leapYears;