PHP: Split array of strings into multi-dimensional array

Question

I have an array of timezones:

$timezones = array(
 'Africa/Abidjan',
 'Africa/Accra',
 ...
 'America/Argentina/Buenos_Aires',
 'America/Argentina/Catamarca',
 ...
 'Pacific/Wallis',
 'UTC',
);

How can I easiest split this array so that I get one like this:

$timezones = array(
 'Africa' => array('Abidjan', 'Accra', ... ),
 'America' => array(..., 'Argentina' => array('Buenos_Aires', 'Catamarca', ...), ...),
 ...
 'Pacific' => array(..., 'Wallis'),
 'UTC',
);

Answer 1

$splitted = array();
foreach ($timezones as $timezone)
{
 $items = explode('/', $timezone);
 add_to_array($splitted, $items);
}
print_r($splitted);
function add_to_array(& $destination, $values)
{
 if (count($values) == 1)
 {
 $destination[] = $values[0];
 }
 else
 {
 $first = array_shift($values);
 add_to_array($destination[$first], $values);
 }
}

Answer 2

Non recursive hackish version using eval():

$output = array();
foreach ( $timezones as $zone ) {
 if ( strpos($zone, '/') !== FALSE ) {
 $str = preg_replace('#/([^/]+)$#', "'][] = '1ドル';", $zone);
 $str = str_replace('/', "']['", $str);
 $str = '$output[\''.$str;
 eval($str);
 } else {
 $output[$zone] = '';
 }
}
print_r($output);

• Gordon: This is str_replace('a', 'i', 'eval'); ;)
• Matteo Riva: There Is More Than One Way... oh wait, it was just for fun :)