what-century-is-it.md

What century is it? ^{6 Kyu}

^{LINK TO THE KATA - STRINGS ALGORITHMS DATE TIME}

Description

Return the century of the input year. The input will always be a 4 digit string, so there is no need for validation.

"1999" --> "20th"
"2011" --> "21st"
"2154" --> "22nd"
"2259" --> "23rd"
"1124" --> "12th"
"2000" --> "20th"

Solution

const whatCentury = year => {
  const century = Math.ceil(Number(year) / 100)
  const suffix =
    century === 11 || century === 12 || century === 13
      ? 'th'
      : century % 10 === 1
      ? 'st'
      : century % 10 === 2
      ? 'nd'
      : century % 10 === 3
      ? 'rd'
      : 'th'

  return `${century}${suffix}`
}