Chapter 10, Problem 10.23PE

(Implement the String class) The String class is provided in the Java library. Provide your own implementation for the following methods (name the new class MyString2):

public MyString2(String s);

public int compare(String s);

public MyString2 substring(int begin);

public MyString2 toUpperCase();

public char[ ] toChars();

public static MyString2 valueOf(boolean b);