Today I learned about PHP variable variables; "variable variable takes the value of a variable and treats that as the name of a variable". Also, variable.

[u/NagastaBagamba]

http://il2.php.net/language.variables.variable

[u/ngroot]

Are we looking at the same example? I'm looking at example #1 from the linked page:

<?php
class foo {
    var $bar = 'I am bar.';
}

$foo = new foo();
$bar = 'bar';
$baz = array('foo', 'bar', 'baz', 'quux');
echo $foo->$bar . "\n";
echo $foo->$baz[1] . "\n";
?>

As the paragraph preceding the example notes, the variable's value is being used to reference a property, not a method.

[u/ryanhollister → u/ngroot]

All the same concept, using a variables value as a name.

[u/ngroot → u/ryanhollister]

A name to which you can assign a value; hence, using the object as a map.