3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = array('a' => '', 'b' => '', 'c' => '', 'd' => '', 'e' => '', ); $bar = array('a' => 'foo', 'd' => 'foo', ); $merged = array_merge($foo, $bar); var_dump($merged);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(5) { ["a"]=> string(3) "foo" ["b"]=> string(0) "" ["c"]=> string(0) "" ["d"]=> string(3) "foo" ["e"]=> string(0) "" }

preferences:
346.92 ms | 406 KiB | 456 Q