OBJECT-ORIENTED THINKING - Introduction to Java Programming: Comprehensive Version - page 407

**10.23

( 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);

10.24

( Implement the Character class ) The Character class is provided in the Java
library. Provide your own implementation for this class. Name the new class
MyCharacter .

**10.25

( New string split method ) The split method in the String class returns an
array of strings consisting of the substrings split by the delimiters. However, the
delimiters are not returned. Implement the following new method that returns
an array of strings consisting of the substrings split by the matching delimiters,
including the matching delimiters.

public static String[] split(String s, String regex)

For example, split("ab#12#453", "#") returns ab , # , 12 , # , 453 in an
array of String , and split("a?b?gf#e", "[?#]") returns a , b , ? , b , gf ,
# , and e in an array of String .

*10.26

( Calculator ) Revise Listing 7.9, Calculator.java, to accept an expression as
a string in which the operands and operator are separated by zero or more
spaces. For example, 3+4 and 3 + 4 are acceptable expressions. Here is a
sample run:

**10.27

( Implement the StringBuilder class ) The StringBuilder class is provided
in the Java library. Provide your own implementation for the following methods
(name the new class MyStringBuilder1 ):

public MyStringBuilder1(String s);
public MyStringBuilder1 append(MyStringBuilder1 s);
public MyStringBuilder1 append( int i);
public int length();
public char charAt( int index);
public MyStringBuilder1 toLowerCase();
public MyStringBuilder1 substring( int begin, int end);
public String toString();