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String Case Change Functions

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.

Hardware Required:

  • Arduino Board

Circuit

There is no circuit for this example, though your Arduino must be connected to your computer via USB.

image developed using Fritzing. For more circuit examples, see the Fritzing project page

Code

/*
  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://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);
}

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