I would like to convert a byte *payload to String, because I want to compare the content of the payload to other String.

void mqttCallbackHandler(char *topic, byte *payload, unsigned int length) 
 {
   String payloadstr = ???
   ...
}

I would like to convert a byte *payload to a String, because I want to compare the content of payload to another String.

void mqttCallbackHandler(char *topic, byte *payload, unsigned int length) {
  String payloadstr = ???
  ...
}