void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  String haxx = "0123456789ABCDEF";
  String ha = "98CDAC23EC9";
  Serial.println(regex(ha, 1));
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}
boolean regex(String text, byte type)
{
  String regex;
  int mx, mn;
  switch (type)
  {
    case 1: /// hex max check
      regex = "0123456789ABCDEF";
       mx = 12;
       mn = 12;
      break;
  }

  int len = text.length();
  Serial.println(len);
  if (len <= mx && len >= mn)
  {Serial.println("starting!");
    for (int i = 0; i < len; i++)
    {
      int check = regex.indexOf(text[i]);
      if (check < 0)
        return false;
    }
    return true;
  }
  else{ Serial.println("Hello, EfbggbgP32!");
    return false; }
}