3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = ['123' => 'abc']; $b = ['123' => 'foobar']; var_dump(array_merge($a, $b)); var_dump($a+$b);
Output for 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 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
array(2) { [0]=> string(3) "abc" [1]=> string(6) "foobar" } array(1) { [123]=> string(3) "abc" }
preferences:
111.84 ms | 1985 KiB | 4 Q