private boolean isAffirmative(final String input){
  requireNonNull(input);
  for (  final String affirmativeString : affirmativeStrings) {
    if (input.equalsIgnoreCase(affirmativeString)) {
      return true;
    }
  }
  return false;
}

private boolean isAffirmative ( final String input ) { requireNonNull ( input ) ; for ( final String affirmativeString : affirmativeStrings ) { if ( input . equalsIgnoreCase ( affirmativeString ) ) { return true ; } } return false ; }
checks if a user ' s input matches one of the affirmative strings .
