Convert names array to sentence structure

names_to_sentence.js

function cleanNameInput(names) {
  return names
    .map(name => name.trim())
    .filter(name => name)
}

function namesToSentence(names = [], options = {}) {
  names = cleanNameInput(names)
  const before = names.slice(0, options.length || -1)
  const after = names.slice(options.length || -1)
  return `${before.join(', ')} and ${(after.length > 1) ? `${after.length} others` : after.join()}`
}

// namesToSentence(['susy', 'john', 'mary', 'sally', 'adam', 'jessa'])
// => "susy, john, mary, sally, adam and jessa"

// namesToSentence(['susy', 'john', 'mary', , , 'jessa'])
// => "susy, john, mary and jessa"

// namesToSentence(['susy', 'john', 'mary', 'sally', 'adam', 'jessa'], { length: 3 })
// => "susy, john, mary and 3 others"