The String case change functions allow you to change the case of a String. They work just as their names imply. toUpperCase() changes the whole string to upper case characters, and toLowerCase() changes the whole String to lower case characters. Only the characters A to Z or a to z are affected.
Arduino or Genuino Board Circuit
There is no circuit for this example, though your board must be connected to your computer via USB and the serial monitor window of the Arduino Software (IDE) should be open.
image developed using Fritzing. For more circuit examples, see the Fritzing project page
/* String Case changes Examples of how to change the case of a string created 27 July 2010 modified 2 Apr 2012 by Tom Igoe http://www.arduino.cc/en/Tutorial/StringCaseChanges This example code is in the public domain. */ 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 } // send an intro: Serial.println("\n\nString case changes:"); Serial.println(); } void loop() { // toUpperCase() changes all letters to upper case: String stringOne = "<html><head><body>"; Serial.println(stringOne); stringOne.toUpperCase(); Serial.println(stringOne); // toLowerCase() changes all letters to lower case: String stringTwo = "</BODY></HTML>"; Serial.println(stringTwo); stringTwo.toLowerCase(); Serial.println(stringTwo); // do nothing while true: while (true); }