[appB] More examples for String immutability

package appB;

public class StringImmutability {

  public static void main(String[] args) {

    stringMethodsCreateNewObjects();

  }

  static void stringMethodsCreateNewObjects() {

    String string = "the text";

    String upperStr = string.toUpperCase();

    System.out.println(string);

    System.out.println(upperStr);

    System.out.println(string.equals(upperStr));

  }

  static void stringsOfTheSameValueAreTheSameObject() {

    String str1 = "customer";

    String str2 = "customer";

    System.out.println(str1 == str2);

  }

  String stringConcatenation() {

    String s = "0";

    for (int i = 1; i < 10; i++) {