Fastest method for testing a fixed phone number pattern

Question

So, the challenge is that we are trying to detect if a string matches a fixed phone number pattern, this is a simple string pattern.

The pattern is:

Answer 1

very fast:

   function tecjam3(pattern) {
  if (pattern.length !== 12) {
    return false;
  }

  code = pattern.charCodeAt(0);
  if (code < 48 || code > 57) return false;
  code = pattern.charCodeAt(1);
  if (code < 48 || code > 57) return false;
  code = pattern.charCodeAt(2);
  if (code < 48 || code > 57) return false;

  code = pattern.charCodeAt(4);
  if (code < 48 || code > 57) return false;
  code = pattern.charCodeAt(5);
  if (code < 48 || code > 57) return false;
  code = pattern.charCodeAt(6);
  if (code < 48 || code > 57) return false;

  code = pattern.charCodeAt(8);
  if (code < 48 || code > 57) return false;
  code = pattern.charCodeAt(9);
  if (code < 48 || code > 57) return false;
  code = pattern.charCodeAt(10);
  if (code < 48 || code > 57) return false;
  code = pattern.charCodeAt(11);
  if (code < 48 || code > 57) return false;

  if (pattern.charAt(3) != '-' || pattern.charAt(7) != '-') return false;

  return true;
}