/* Appending to Strings using the += operator and concat() Examples of how to append different data types to strings created 27 July 2010 modified 2 Apr 2012 by Tom Igoe http://www.arduino.cc/en/Tutorial/StringAppendOperator This example code is in the public domain. */ String stringOne, stringTwo; void setup() { // Open serial communications and wait for port to open: Serial.begin(9600); while (!Serial) { ; // wait for serial port to connect. Needed for Leonardo only } stringOne = String("Sensor "); stringTwo = String("value"); // send an intro: Serial.println("\n\nAppending to a string:"); Serial.println(); } void loop() { Serial.println(stringOne); // prints "Sensor " // adding a string to a string: stringOne += stringTwo; Serial.println(stringOne); // prints "Sensor value" // adding a constant string to a string: stringOne += " for input "; Serial.println(stringOne); // prints "Sensor value for input" // adding a constant character to a string: stringOne += 'A'; Serial.println(stringOne); // prints "Sensor value for input A" // adding a constant integer to a string: stringOne += 0; Serial.println(stringOne); // prints "Sensor value for input A0" // adding a constant string to a string: stringOne += ": "; Serial.println(stringOne); // prints "Sensor value for input" // adding a variable integer to a string: stringOne += analogRead(A0); Serial.println(stringOne); // prints "Sensor value for input A0: 456" or whatever analogRead(A0) is Serial.println("\n\nchanging the Strings' values"); stringOne = "A long integer: "; stringTwo = "The millis(): "; // adding a constant long integer to a string: stringOne += 123456789; Serial.println(stringOne); // prints "A long integer: 123456789" // using concat() to add a long variable to a string: stringTwo.concat(millis()); Serial.println(stringTwo); // prints "The millis(): 43534" or whatever the value of the millis() is // do nothing while true: while (true); }