public class replace_character {

  public static void main(String[] args) {
    String str = "The quick brown fox jumps over the lazy dog.";

    // Replace all the 'd' characters with 'f' characters.
    String new_str = str.replace('d', 'f');

    // Display the strings for comparison.
    System.out.println("Original string: " + str);
    System.out.println("New String: " + new_str);
  }
}