numberToHex function

String numberToHex(dynamic number, { bool pad = false, bool include0x = false, int? forcePadLen, })

Converts the number, which can either be a dart int or a BigInt, into a hexadecimal representation. The number needs to be positive or zero.

When pad is set to true, this method will prefix a zero so that the result will have an even length. Further, if forcePadLen is not null and the result has a length smaller than forcePadLen, the rest will be left-padded with zeroes. Note that forcePadLen refers to the string length, meaning that one byte has a length of 2. When include0x is set to true, the output wil have "0x" prepended to it after any padding is done.

Implementation

String numberToHex(
  dynamic number, {
  bool pad = false,
  bool include0x = false,
  int? forcePadLen,
}) {
  String toHexSimple() {
    if (number is int) {
      return number.toRadixString(16);
    } else if (number is BigInt) {
      return number.toRadixString(16);
    }
    throw TypeError();
  }

  String hexString = toHexSimple();
  if (pad && !hexString.length.isEven) {
    hexString = '0$hexString';
  }
  if (forcePadLen != null) {
    hexString = hexString.padLeft(forcePadLen, '0');
  }
  if (include0x) {
    hexString = '0x$hexString';
  }
  return hexString;
}