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This example is for Wiring version 1.0 build 0100+. If you have a previous version, use the examples included with your software. If you see any errors or have comments, please let us know.

String replace() by Tom Igoe
Examples of how to replace characters or substrings of a string

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

    void loop()
    {
      String stringOne = "<html><head><body>";
      Serial.println(stringOne);
      // replace() changes all instances of one substring with another:
      stringOne.replace("<", "</");
      String stringTwo = stringOne;
      Serial.println(stringTwo);

      // you can also use replace() on single characters:
      String normalString = "bookkeeper";
      Serial.println("normal: " + normalString);
      normalString.replace('o', '0');
      String leetString = normalString;
      leetString.replace('e', '3');
      Serial.println("l33tspeak: " + leetString);

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