Calculate age

calculate_age.js

function calculateAge(year, month, date) {
  const bornDate = new Date(year, month - 1, date);
  const nowDate = new Date();
  const bornYear = bornDate.getFullYear();
  const nowYear = nowDate.getFullYear();
  let age = nowYear - bornYear - 1;
  if (
    nowDate.getMonth() >= bornDate.getMonth() &&
    nowDate.getDate() >= bornDate.getDate()
  ) {
    age += 1;
  }
  return age;
}