Discussion on: Daily Challenge #54 - What century is it?

[Cagatay Kaya]

A length Javascript solution, but I did not want to divide by 100.

const century = year => {
  const yearString = year.toString();
  const n = String(year).length;
  if (n - 3 < 0) {
    console.log("0th century");
  } else {
    console.log(digitYears(yearString, n));
  }
};

const digitYears = (yearString, n) => {
  const toIntAgain = parseInt(yearString[n - 3]) + 1;
  const edges = parseInt(yearString.slice(n - 4, n - 2)) + 1;
  if (edges == 11 || edges == 12 || edges == 13) {
    return `${yearString.slice(0, n - 3)}${toIntAgain}th century`;
  } else {
    const ending = endingDetermine(toIntAgain);
    return `${yearString.slice(0, n - 3)}${toIntAgain}${ending} century`;
  }
};

const endingDetermine = digit => {
  let ending = "";
  switch (digit) {
    case 1:
      ending = "st";
      break;
    case 2:
      ending = "nd";
      break;
    case 3:
      ending = "rd";
      break;
    default:
      ending = "th";
      break;
  }
  return ending;
};

Tried it with a few different years including the edge cases.

century(11034); //111th century
century(15134); //152nd century
century(16234); //163th century
century(942); //10th century
century(2042); //21st century
century(1342); //14th century
century(1242); //13th century
century(52); //0th century