Strings, Characters and Regular Expressions - Java: How to Program Early Objects - page 615

17
18 for ( char character : charArray)

19 System.out.print(character);

20
21

buffer.setCharAt( 0 , 'H' );
buffer.setCharAt( 6 , 'T') ;

22

23

System.out.printf( "%n%nbuffer = %s" , buffer.toString());

24
25

buffer.reverse();

26

System.out.printf( "%n%nbuffer = %s%n" , buffer.toString());

27

}

28

} // end class StringBuilderChars

buffer = hello there
Character at 0: h
Character at 4: o

The characters are: hello there

buffer = Hello There

buffer = erehT olleH

Fig. 14.12 | StringBuilder methods charAt , setCharAt , getChars and reverse . (Part 2
of 2.)

14.4.4 StringBuilder append Methods
Class StringBuilder provides overloaded append methods (Fig. 14.13) to allow values of
various types to be appended to the end of a StringBuilder . Versions are provided for
each of the primitive types and for character arrays, String s, Object s, and more. (Remem-
ber that method toString produces a string representation of any Object .) Each method
takes its argument, converts it to a string and appends it to the StringBuilder .

1 // Fig. 14.13: StringBuilderAppend.java

2 // StringBuilder append methods.

3
4 public class StringBuilderAppend

5 {

6 public static void main(String[] args)

7 {

8 Object objectRef = "hello" ;

9 String string = "goodbye" ;

10 char [] charArray = { 'a' , 'b' , 'c' , 'd' , 'e' , 'f' };

11 boolean booleanValue = true ;

12 char characterValue = 'Z' ;

13 int integerValue = 7 ;

14 long longValue = 10000000000L ;

15 float floatValue = 2.5f ;

16 double doubleValue = 33.333 ;

Fig. 14.13 | StringBuilder append methods. (Part 1 of 2.)