bytesToHex function

String bytesToHex(List<int> bytes, { bool include0x = false, int? forcePadLength, bool padToEvenLength = false, })

Converts the bytes given as a list of integers into a hexadecimal representation.

If any of the bytes is outside of the range 0, 256, the method will throw. The outcome of this function will prefix a 0 if it would otherwise not be of even length. If include0x is set, it will prefix "0x" to the hexadecimal representation. If forcePadLength is set, the hexadecimal representation will be expanded with zeroes until the desired length is reached. The "0x" prefix does not count for the length.

Implementation

String bytesToHex(
  List<int> bytes, {
  bool include0x = false,
  int? forcePadLength,
  bool padToEvenLength = false,
}) {
  var encoded = hex.encode(bytes);

  if (forcePadLength != null) {
    assert(forcePadLength >= encoded.length);

    final padding = forcePadLength - encoded.length;
    encoded = ('0' * padding) + encoded;
  }

  if (padToEvenLength && encoded.length % 2 != 0) {
    encoded = '0$encoded';
  }

  return (include0x ? '0x' : '') + encoded;
}