How to Convert Byte Array to Hexstring Arduino Platform

convert_byte_array.ino

void setup() {
  byte example[] = {0x31, 0x32, 0x33, 0x34};
  int length = 4;

  String result = "";
  String hexstring = "";

  for(int i = 0; i < length; i++) {
    if(example[i] < 0x10) {
      hexstring += '0';
    }

    hexstring += String(example[i], HEX);
  }

  result = HexString2ASCIIString(hexstring);

  Serial.begin(9600);
  Serial.println(result);
}

void loop() {

}

String HexString2ASCIIString(String hexstring) {
  String temp = "", sub = "", result;
  char buf[3];
  for(int i = 0; i < hexstring.length(); i += 2){
    sub = hexstring.substring(i, i+2);
    sub.toCharArray(buf, 3);
    char b = (char)strtol(buf, 0, 16);
    if(b == '\0')
      break;
    temp += b;
  }
  return temp;
}

veryyyy thank you!