Errata Home to Cookwood Press

This list of errata is from the SECOND EDITION of the book. The errata from the First Edition can be found on its own page.

You can also view the errata by date posted.

Acknowledgements (page 4)

Dave Hirano should be listed as Dave Bene.

Page 120 (April 14, 2002)

The line references in the explanations (in the pink block and in the caption) are incorrect.

It should look like this (with changes in red):

11   The autoincrement operator adds 1 to the value of $counter. The result is then assigned back to $counter.

12   The autoincrement operator again adds 1 to the value of $counter, and assigns the result back to $counter. Then, it assigns the result of the operation to $watch. Note that $counter is equal to $watch.

15   We reassign the initial visitor-entered start value to $counter so that we can compare the two operators on an even footing.

16   The autoincrement operator adds 1 to the value of $counter. The result is then assigned back to $counter. There is no difference here from line 11.

17   The value of $counter is assigned to $watch, and then the autoincrement operator adds 1 to the current value of $counter and assigns the result back to $counter. Now $counter and $watch have different values. Compare these results with the results from line 12.

Figure 10.30  If you're not assigning the result of the entire expression to another variable, the placement of the autoincrement operators doesn't matter (lines 11 and 16). It's when you assign the result to a new variable ($watch), as in lines 12 and 17, that the order becomes important.

So sorry for all that. What a mess! (And thanks to Jack Nation.)


Sorry for the inconvenience!

If you find an error in the book, I'd like to know about it. Please drop me a note so I can post it here and correct it in future reprints and editions. Thanks.

©Copyright 1998, 2001 by Elizabeth Castro. All rights reserved. Hey, even my mistakes are mine!
Please don't copy this page. Instead, link to it! Thanks.

For more information about Perl and CGI, check out my book, Perl and CGI for the World Wide Web: Visual QuickStart Guide, published by Peachpit Press.