3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = [ 'a' => 42, ]; $foo['a']++; $foo['b']++;
Output for 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
Warning: Undefined array key "b" in /in/H2lp7 on line 7
Output for 5.6.23 - 5.6.40, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33
Notice: Undefined index: b in /in/H2lp7 on line 7
Output for 4.3.0
Parse error: parse error, unexpected '[' in /in/H2lp7 on line 3
Process exited with code 255.
preferences:
115.53 ms | 1392 KiB | 4 Q