By opening a terminal and typing

$ node
> http.STATUS_CODES
{ '100': 'Continue',
  '101': 'Switching Protocols',
  '102': 'Processing',
  '200': 'OK',
  '201': 'Created',
  '202': 'Accepted',
  '203': 'Non-Authoritative Information',
  '204': 'No Content',
  '205': 'Reset Content',
  '206': 'Partial Content',
  '207': 'Multi-Status',
  '300': 'Multiple Choices',
  '301': 'Moved Permanently',
  '302': 'Moved Temporarily',
  '303': 'See Other',