String startWith() and endsWith() by Tom Igoe

Examples of how to use startsWith() and endsWith() in a String

void setup()
{
  Serial.begin(9600);
  Serial.println("\n\nString startsWith() and endsWith():");
}

void loop()
{
  // startsWith() checks to see if a String starts with a particular substring:
  String stringOne = "HTTP/1.1 200 OK";
  Serial.println(stringOne);
  if (stringOne.startsWith("HTTP/1.1"))
  {
    Serial.println("Server's using http version 1.1");
  }

  // you can also look for startsWith() at an offset position in the string:
  stringOne = "HTTP/1.1 200 OK";
  if (stringOne.startsWith("200 OK", 9))
  {
    Serial.println("Got an OK from the server");
  }

  // endsWith() checks to see if a String ends with a particular character:
  String sensorReading = "sensor = ";
  sensorReading += analogRead(A0);
  Serial.print(sensorReading);
  if (sensorReading.endsWith(0))
  {
    Serial.println(". This reading is divisible by ten");
  }
  else
  {
    Serial.println(". This reading is not divisible by ten");
  }

  // do nothing while true:
  while (true);
}