$string = "  \n Hello World!";
echo ltrim($string);

Hello World!

echo ltrim($string, " \nA..Ha..z!");
// All capital letters between A and H, all lowercase letters, exclamation point, space, and newline

World!

rtrim()

$string = "!Hello World42! \t\t";
echo rtrim($string);

!Hello World42!

echo rtrim($string, " \t!0..9");
// Range included is all numbers between 0 and 9, tab, space, and exclamation point.

!Hello World

Returns an array with they keys…

It should read:

Returns an array with the keys…

Returns: 1 if matched, 0 if no match, and FALSE on error.

// file.txt contains the sentence: Hello World!
$filename = 'file.txt';
$file = fopen($filename, 'r');
$string = fread( $file, filesize($filename) );
var_dump($string);
// file.txt now contains at the end: Hello World!

You’ll notice that this is the same tip as fread() and doesn’t belong. It should be considered ‘removed’.

pg. 162

preg_match_all: 157-158

pg. 161

array_combine: 73
array_key_exists: 79-80

In the Function Index (pg. 161), array_key_exists() is listed as page 82. However, it is actually on page 79.

Feel free to submit a correction yourself if you find any!

In the book, the print_r() function is described as follows:

Output the contents of $variable . Typically used to display the contents of an array.

However, there is also an optional flag for the print_r() function that makes the function return the output rather than printing it to the screen. Therefore, the section of the book should be amended as follows:

return – [optional] $boolean default: FALSE, print output
Output the contents of $variable. Typically used to display the contents of an array. If return is set to TRUE, print_r() returns the output rather than displaying it, such as when storing it in a variable.

The function has the following correct syntax:

mysql_result(resource, row[, column])

However, in the explanation paragraph, 2^nd sentence, it uses the term field erroneously instead of the term column. It should read as follows:

If column is specified instead of the value of the
first column, the specified column is retrieved (can be referenced by number
starting with 0 or by name/alias).

It’s the little things, like changing the term used to be clearer to the reader and forgetting to update everything.

Book version:

\w – Letter (a-z, A-Z)

Correct version:

\w – Letter, Digit, Underscore [a-zA-Z0-9_]

This is similar to the syntax for alphanumeric: [:alnum:]

The description in the book reads:

$_SERVER[‘QUERY_STRING’] – The current scripts path

This description is the same as the entry above, because I made a bad edit (copy/paste for formatting). The correct description would be as follows:

$_SERVER[‘QUERY_STRING’] – The current query string (without the question mark)

The example is correct and accurate, and luckily this is painfully obvious thanks to the name of the key QUERY_STRING in the $_SERVER array.