toPigLatin.js

function toPigLatin(strings) {
  const words = strings.split(' ')
  const startAt = ''

  function swapAndTranslate(accumulator, currentAlphabet) {
    const translator = ['a', 'y']
    let swapCharacter = [...currentAlphabet.toLowerCase()]
    const firstAlphabet = swapCharacter[0]

    swapCharacter[swapCharacter.length] = firstAlphabet
    swapCharacter = [
      ...swapCharacter.slice(1),
      ...translator
    ].join('')

    const results = accumulator + swapCharacter
    return results.charAt(0).toUpperCase() + results.slice(1) + ' '
  }
  return words
    .reduce(swapAndTranslate, startAt)
    .trim()
}

toPigLatin('The quick brown fox')