Errata

The following statement in book:

$ingredient = $ammonia xor $bleach;

should be written as:

$ingredient = ($ammonia xor $bleach);

The additional parentheses are required due to operator precedence, as assignment holds tighter than xor. For instance,

$ammonia = 0; $bleach = 1;
$ingredient = $ammonia xor $bleach;
echo $ingredient;

print zero, even if it's obvious that result of 0 xor 1 is one. This is because the assignment statement is parsed as:

($ingredient = $ammonia) xor $bleach;

hence $ingredient gets zero, than xor operator with $bleach results into one, but this operation is throwed out, as it operates in void context.

Note from the Author or Editor:
This is correct. The parentheses are required in this instance.

In Example 3-9 when running the example exactly as printed in the book the PHP processor produces no output due to a missing statement (echo $out;)at the end of the code before the end of the PHP (?>).

I will paste the code as it is in the book, then I will paste it again but will add the missing statement followed by a comment indicating that this is where I've added my correction like this:

"// This is where I've added my correction to make the code work"

Example 3-9 as it's printed in the book:
------------------------------------
<?php
$author = "Scott Adams";
$out = <<<_END
Normal people believe that if it ain't broke, don't fix it.
Engineers believe that if it ain't broke, it doesn't have enough
features yet.
- $author.
_END;
?>
------------------------------------

And with the correction needed to produce results.
------------------------------------
<?php
$author = "Scott Adams";
$out = <<<_END
Normal people believe that if it ain't broke, don't fix it.
Engineers believe that if it ain't broke, it doesn't have enough
features yet.
- $author.
_END;
echo $out // This is where I've added my correction to make the code work
?>
------------------------------------

I'm a new programmer, to begin with, and am completely new to PHP, and couldn't figure out why something from a book wouldn't run, until Ah hahh, using knowledge from the book I found the problem. I guess according to example 3-8 I am smart enough to debug...
Thanks for your attention.

Matthew Lagasse

Note from the Author or Editor:
The following statement requires adding immediately prior to the closing ?> tag of Example 3-9:

echo $out;

The unary negation operator is ! (an exclamation mark), not a minus sign (-).

"Returning values from a function by reference" should be
"Passing values to a function by reference".

Missing dollar sign before 'object':

"like this: object = new Class. " should be "like this: $object = new Class. "

"…because PHP implicitly declares the variable $object1->name for you."

should be

"…because PHP implicitly declares the property $object1->name for you."

"You achieve this using the extends operator."

should be:

"You achieve this using the extends keyword."

"... by means of the extends operator."

Should be:

"... by the means of the extends keyword."

format "G" does not have a leading zero, but "H" does

Text uses February as an example, but sample code uses September.

The else statement in Example 7-17 is not closed.
It should be
foreach($output as $line) echo htmlspecialchars("$line\n");
echo "</pre>";
}
?>
instead of
foreach($output as $line) echo htmlspecialchars("$line\n");
echo "</pre>";
?>

Sample code explicetely uses MyISAM (for later use of fulltext indexes). New standard is InnoDB which also supports fulltext. Code could be simplified.

BINARY(n) or BYTE(n):

There is no data type "BYTE" in MySQL (but in Oracle).
The term "CHAR_BYTE" exists in MySQL as an alias for BINARY.

AUTO_INCREMENT is not a data type but an attribute.

"And finally, I set no limit to the year column’s index, because it’s an integer, not a string." but "year" is defined as data type CHAR.

I suggest to change the sentence to:

"And finally, I set no limit to the year column’s index, because it has a clearly defined length of 4 characters."

The book states: "FULLTEXT indexes can be used only with MyISAM tables"
This is incorrect, InnoDB tables can also have FULLTEXT indexes in MySQL5.6.

Note from the Author or Editor:
This bullet point should be updated by inserting the following in front of the existing text:

Since MySQL 5.6 InnoDB tables can use FULLTEXT indexes, but prior to that

isbn="9781598184891 ";

Example (also downloadable code) contains an additional space before the closing double quote.

Calling data_seek over mysqli_result is unnecessary in these examples. It set the pointer to the same row it's already pointing and may be removed

without any further modification from
Example 10-5. Fetching results one row at a time
Example 10-6. Inserting and deleting using sqltest.php
Example 10-8. Describing the table cats
Example 10-11. Retrieving rows from the cats table
Example 10-15. Performing a secondary query

and with slight modifications (*) from
Example 10-4. Fetching results one cell at a time
(*) Calling fetch_assoc() only one time per row and saving the result

Code currently reads:
echo "The Insert ID was: " .$result->insert_id;

This results in an error message: "Trying to get property of non-object"

Code should read:
echo "The Insert ID was: " .$conn->insert_id;

Note from the Author or Editor:
In Example 10-14 this line:

echo "The Insert ID was: " . $result->insert_id;

Should be replaced with:

echo "The Insert ID was: " . $conn->insert_id;

Also, near the bottom of the page, the line that reads:

$insertID = $result->insert_id;

Should be changed to:

$insertID = $conn->insert_id;

The code of additional query is as follows:
$subresult = $conn->query($query);

Should be rather
$subresult = $conn->query($subquery);

Otherwise it again refers to the first query and doesn't produce expected results.

Note from the Author or Editor:
In Example 10-15 this line:

$subresult = $conn->query(query);

Should be replaced with:

$subresult = $conn->query($subquery);

A little bit of purism here, but in the hashing discussion, it is said:

"Salting is simply a matter of adding
some text that only we know about to each parameter to be encrypted."

It should probably say "hashed" instead of "encrypted," since encryption is usually contrasted with hashing with the one/two-way function difference.

Hello Robin,

I think there is an error in the last statement in bold where the original is:

<a href=continue.php>

and I believe it should be:

<a href='continue.php'>

Not such a horrible issue though... above all if I can spot it :o)

Note from the Author or Editor:
This is not exactly an error because all browsers allow URLs to not be encapsulated in quotation marks. However, to show best practice, I agree that the URL should be quoted.

The CSS class .signup is defined but not used.
To get the same result as Figure16-1 the property class="signup" should be added to the <table> tag.

Note from the Author or Editor:
The first line of HTML in the <body> section should read:

<table class="signup" border="0" cellpadding="2" cellspacing="5" bgcolor="#eeeeee">

The function isNaN returns false when an empty string is passed because JavaScript interprets it as a 0.
So inside the validateAge function the first check should be something like
if (field == "" || isNaN(field)) return "No Age was entered.\n"
to get the same result as Figure 16-2

Note from the Author or Editor:
That is interesting. Indeed, tests confirm that isNaN() treats the empty string as if it were a number. Your solution to this is correct: Simply replace the first line of the function validateAge() with:

if (field == "" || isNaN(field)) return "No Age was entered.\n"

The closing tag of the <div> element is written </fiv> (instead of the correct </div>).

Note from the Author or Editor:
The </fiv> tag should read </div>

240,20 should be 240,240.
"Then an arc is drawn using imaginary tangent lines from that location to position 240,20, and from there to location 460,20."
I found it confusing me, so I guess 240,240 will be reasonable.Thanks for your attention.
Yuxin Sun

On page 664 of the book, bottom paragraph it reads "See chapter 13 for more details on how to do this", they are referring to hashed passwords.

problem: chapter 13 does *not* contain any such information ,its actually found in chapter 12

Note from the Author or Editor:
Thanks - the correct Chapter is, indeed, 12.

Chapter 8 Answers, Answer 3 states that the password is 'newpassword'.

However the original question (page 206) states that the password should be 'newpass'.