RadioHead rf95.lastRssi() to String

Projects Programming
2 
Serial.print(rf95.lastRssi(), DEC);

prints the value returned by the rf95.lastRssi() function

int iRssi = (rf95.lastRssi(), DEC);
Serial.println(sRssi);

prints a variable, the origin of which you do not say. Is it any surprise that they are different ?

What variable type does the rf95.lastRssi() return and why do you want to convert it to a String ?