3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = new stdClass(); $bar = 'bar'; $foo->$bar = array(); // works as expected var_dump($foo); $foo->$bar[] = 'baz'; // oops
Output for 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
object(stdClass)#1 (1) { ["bar"]=> array(0) { } }
Output for 4.3.2 - 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
Fatal error: Cannot use [] for reading in /in/U1QAu on line 7
Process exited with code 255.
Output for 4.3.0 - 4.3.1
Fatal error: Cannot use [] for reading in /in/U1QAu on line 7

preferences:
327.21 ms | 401 KiB | 455 Q