Convert byte array to hex string (v7)

Revision 7 of this benchmark created by Hermann Stamm-Wilbrandt on

Description

Was only intended to be a oneline solution, but appears to outperform the other implementations by orders or magnitude ...

Setup

var byteArrayData = [],
      i = 0;
    while (i < 10000) {
      byteArrayData.push(Math.floor(Math.random() * 255));
      i++;
    }

Teardown


    byteArrayData = [];

Test runner

Ready to run.

Testing in
TestOps/sec
String length compare
var ret = "",
  i = 0,
  len = byteArrayData.length;
while (i < len) {
  var h = byteArrayData[i].toString(16);
  if (h.length < 2) {
    h = "0" + h;
  }
  ret += h;
  i++;
}
ready
Byte value compare inline.
var ret = "",
  i = 0,
  len = byteArrayData.length;
while (i < len) {
  var a = byteArrayData[i];
  var h = (a < 10 ? "0" : "") + a.toString(16);
  ret += h;
  i++;
}
ready
Byte value compare expanded
var ret = "",
  i = 0,
  len = byteArrayData.length;
while (i < len) {
  var a = byteArrayData[i];
  var h = a.toString(16);
  if (a < 10) {
    h = "0" + h;
  }
  ret += h;
  i++;
}
ready
Byte value compare dupe
var ret = "",
  i = 0,
  len = byteArrayData.length;
while (i < len) {
  var a = byteArrayData[i],
    h;
  if (a < 10) {
    h = "0" + a.toString(16);
  } else {
    h = a.toString(16);
  }
  ret += h;
  i++;
}
ready
recursive oneliner
// convert byte array to hex string
function _(a,  /* aux. var */ b) {
  if (b = a.shift()) { return ("0"+b.toString(16)).slice(b>=0x10) + _(a); }
}

var ret = _(byteArrayData);
ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.