payloadAsString doesn't work as expected?

[white-rabbit07]

Hi. I used this example
https://github.com/don/NDEF/blob/master/examples/ReadTagExtended/ReadTagExtended.ino
to read a RFID-Tag and compare the written text with a given string. It doesn't work as expected and as far as I can tell it's because of a 0x00 that is saved with the string.

I tried this:
if (payloadAsString == Hammer) {Serial.println(" The object is a Hammer"); }
... but it fails.

This snippet seems to be the problem:
String payloadAsString = ""; for (int c = 0; c < payloadLength; c++) { payloadAsString += (char)payload[c]; }

Any hints what to change?

[white-rabbit07]

a possible workaround:
String payloadAsString = ""; for (int c = 1; c < payloadLength; c++) { payloadAsString += (char)payload[c]; }
by using c=1 the initial 0x00 won't be read!

[white-rabbit07]

https://forum.arduino.cc/index.php?topic=426988.0