<?php
// Adapted from last example on http://nikic.github.io/2015/05/05/Internal-value-representation-in-PHP-7-part-1
$a = array(); // $a -> zend_array_1(refcount=1, value=[])
$b = $a; // $a, $b, -> zend_array_1(refcount=2, value=[])
$c = $b; // $a, $b, $c -> zend_array_1(refcount=3, value=[])
$x = $c; // $a, $b, $c, $x -> zend_array_1(refcount=4, value=[])
$d =& $c;
$y =& $d; // $a, $b, $x -> zend_array_1(refcount=4, value=[])
// $c, $d, $y -> zend_reference_1(refcount=3) ---^
echo "Before\n";
debug_zval_dump($a);
debug_zval_dump($b);
debug_zval_dump($c);
debug_zval_dump($d);
$d[] = 1; // $a, $b, $x -> zend_array_1(refcount=3, value=[])
// $c, $d, $y -> zend_reference_1(refcount=3) -> zend_array_2(refcount=1, value=[1])
echo "After\n";
debug_zval_dump($a);
debug_zval_dump($b);
debug_zval_dump($c);
debug_zval_dump($d);
preferences:
115.31 ms | 404 KiB | 5 Q