Re: Java String Manipulation - Can this be made more efficient?

From:
Daniel Pitts <newsgroup.spamfilter@virtualinfinity.net>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 20 May 2008 14:44:56 -0700
Message-ID:
<4832d59e$0$12750$7836cce5@newsrazor.net>
Roedy Green wrote:

On Tue, 20 May 2008 10:30:48 -0700, Man Alive <nopsam@example.com>
wrote, quoted or indirectly quoted someone who said :

int commaLocation = stringName.indexOf(",");
int stringLengthBeforeComma = (stringName.length() - (commaLocation
+1));
System.out.Println("Part of String before comma: "
+stringName.substring(0,stringLengthBeforeComma));


I would code that as:

final int commaPlace = s.indexOf( ',' );
if ( commaPlace < 0 )
   {
  throw new IllegalArgumentException( "missing comma");
   }

final String state = s.substring( 0, commaPlace );
final String city = s.substring( commaPlace+1 );

other ways, especially if you had more fields.

1. use a regex spit. See http://mindprod.com/jgloss/regex.html

2. use CSVReader See http://mindprod.com/jgloss/csv.html

regex split is actually slower than a hand-coded indexOf based parser.
On the other hand, it is easier to get correct. If this is something
that needs to happen thousands of times per second, then don't use
regex. If it's something that happens once when a user clicks go, use
regex :-)

--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>

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