Demo copying references within array

array_references.php

<?php

error_reporting(E_ALL | E_STRICT);

$array = array();
$var = 5;

$array[0] =& $var;

// visible reference
#var_dump($array);

$clone = $array;

// clone has reference
#var_dump($clone);

function param_value($param)
{
	// parameter has reference
	var_dump($param);
}

#param_value($clone);


$original = array();
$var_one = 'a';

$original[0] =& $var_one;
$original[1] = 'b';

$second = array();
$var_two = 'c';

$second[0] =& $var_two;
$second[1] = 'd';

// Works for reference, but not value
#$mapped['$1'] =& $original[0];
#$mapped['$2'] =& $original[1];

// Works for reference and value
$mapped = $original;
$mapped['$1'] =& $mapped[0]; unset($mapped[0]);
$mapped['$2'] =& $mapped[1]; unset($mapped[1]);

// Still works for reference and value
$appended = $second;
$mapped['$3'] =& $appended[0]; unset($appended[0]);
$mapped['$4'] =& $appended[1]; unset($appended[1]);

$var_one = 'y';
$var_two = 'z';

#var_dump($original, $second, $mapped);


function append($incoming, & $result)
{
	$duplicate = $incoming;

	foreach (array_keys($incoming) as $key)
	{
		$result['$'.(count($result) + 1)] =& $duplicate[$key];
		unset($duplicate[$key]);
	}
}

$output = array();
append($original, $output);
append($second, $output);

var_dump($original, $second, $output);