Tim Keller

A seldom used, but incredibly useful, aspect of PHP is the ability to reference variables by name, based on the contents of a variable. Don’t worry if that sentence didn’t make sense to you. Let’s see an example:

$a = "hello";       // $a is "hello"
$$a = "world";    // Now $hello = "world"
echo "$a ${$a}"   // outputs "hello world"
echo "$a $hello" // also ouptuts "hello world"

This is useful in the situation that you need to access an object class variable at runtime. Let’s say we have three class variables:

$this->cycle_1_mark
$this->cycle_2_mark
$this->cycle_3_mark

At runtime, we have a variable $semester which holds the current semester. To it access it, we do something like:

$myObject = new Object();
echo $myObject->{"cycle_$semester_mark"};  // outputs the value for the substituted class variable

More on PHP.net:Variable Variables.

This summer has got to be the very best ever! Here are links to some of my photos. Enjoy!

Amy and I get engaged

Christmas Celebration

Congratulations Barack Obama!

What did Joe the Plumber just say to Meghan McCain?

• Firebird Database
• OpenAFS (Andrew FileSystem)
• eJabberd
• Ruby
• Mechanize
• Rsync and RSnapshot
• MySQL Replication

For the first time in years I think I may be excited about Windows (in particular Windows 7). Until I get some time to do my own review of the M3 pre-beta, here are links to some of my favourite links.

• http://www.winsupersite.com/win7/win7_preview.asp
• http://www.winsupersite.com/win7/win7_preview_02.asp
• http://www.winsupersite.com/win7/win7_m3_screens_02.asp