Strings and Things - Java - page 90

sb2 . append ( "World" );

// Get the StringBuilder's value as a String, and print it.
String s2 = sb2 . toString ();
System . out . println ( s2 );

// Now do the above all over again, but in a more
// concise (and typical "real-world" Java) fashion.

System . out . println (
new

new StringBuilder ()
. append ( "Hello" )
. append ( ',' )
. append ( ' ' )
. append ( "World" ));

}

}

In fact, all the methods that modify more than one character of a StringBuilder 's contents
(i.e., append() , delete() , deleteCharAt() , insert() , replace() , and reverse() ) return
a reference to the builder object to facilitate this “fluent API” style of coding.

As another example of using a StringBuilder , consider the need to convert a list of items
into a comma-separated list, while avoiding getting an extra comma after the last element of
the list. Code for this is shown in Example 3-3 .

Example 3-3. StringBuilderCommaList.java
// Method using regexp split
StringBuilder sb1 = new

new StringBuilder ();

for for ( String word : SAMPLE_STRING . split ( " " )) {

iif ( sb1 . length () > 0 ) {
sb1 . append ( ", " );

}
sb1 . append ( word );

}
System . out . println ( sb1 );

// Method using a StringTokenizer
StringTokenizer st = new

new StringTokenizer ( SAMPLE_STRING );
StringBuilder sb2 = new new StringBuilder ();

while while ( st . hasMoreElements ()) {

sb2 . append ( st . nextToken ());
iif ( st . hasMoreElements ()) {
sb2 . append ( ", " );