function bin2hex (s) {
  // http://kevin.vanzonneveld.net
  // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   bugfixed by: Onno Marsman
  // +   bugfixed by: Linuxworld
  // +   improved by: ntoniazzi (http://phpjs.org/functions/bin2hex:361#comment_177616)
  // *     example 1: bin2hex('Kev');
  // *     returns 1: '4b6576'
  // *     example 2: bin2hex(String.fromCharCode(0x00));
  // *     returns 2: '00'

  var i, l, o = "", n;

  s += "";

  for (i = 0, l = s.length; i < l; i++) {
    n = s.charCodeAt(i).toString(16)
    o += n.length < 2 ? "0" + n : n;
  }

  return o;
}

bin2hex('Kev');

'4b6576'

bin2hex(String.fromCharCode(0x00));

'00'