3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $def = array( 1 => 'on', 2 => 'on', 3 => 'on' ); $fill = array( 2 => 'off' ); $res = array_merge($fill, $def); $res2 = array_merge($def, $fill); print_r($res); print_r($res2); function array_merge_custom($first, $second) { $result = array(); foreach($first as $key => $value) { $result[$key] = $value; } foreach($second as $key => $value) { $result[$key] = $value; } return $result; } $res3 = array_merge_custom($def, $fill); print_r($res3);
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
Array ( [0] => off [1] => on [2] => on [3] => on ) Array ( [0] => on [1] => on [2] => on [3] => off ) Array ( [1] => on [2] => off [3] => on )