String text = "Peter,Paul,Mary"; // an example string
String message = text; // holds text not yet split
int commaPosition; // the position of the next comma in the string
void setup()
{
 Serial.begin(9600);
 
 Serial.println(message); // show the source string
 do
 {

 commaPosition = message.indexOf(',');
 if(commaPosition != -1)
 {
 Serial.println( message.substring(0,commaPosition));
 message = message.substring(commaPosition+1, message.length());
 }
 else
 { // here after the last comma is found
 if(message.length() > 0)
 Serial.println(message); // if there is text after the last comma,
 // print it
 }
 }
 while(commaPosition >=0);
}
void loop()
{
}