3v4l.org

run code in 500+ PHP versions simultaneously
<?php $a = array(); $a[-5] = "-5"; $a[] = "after -5"; $b = array( -5 => "-5" ); $b[] = "after -5"; var_dump($a, $b);
Output for 8.3.0 - 8.3.32, 8.4.1 - 8.4.23, 8.5.0 - 8.5.8
array(2) { [-5]=> string(2) "-5" [-4]=> string(8) "after -5" } array(2) { [-5]=> string(2) "-5" [-4]=> string(8) "after -5" }
Output for 8.0.1 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.32
array(2) { [-5]=> string(2) "-5" [0]=> string(8) "after -5" } array(2) { [-5]=> string(2) "-5" [-4]=> string(8) "after -5" }

preferences:
78.28 ms | 1166 KiB | 4 Q