3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = 'foo'; $bar = new stdClass; $bar->$foo = array(10,20,30); var_dump($bar->$foo); $bar->{$foo[0]} = 42; $bar->$foo[0] = 42; var_dump($bar);
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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(3) { [0]=> int(10) [1]=> int(20) [2]=> int(30) } object(stdClass)#1 (2) { ["foo"]=> array(3) { [0]=> int(42) [1]=> int(20) [2]=> int(30) } ["f"]=> int(42) }
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40
array(3) { [0]=> int(10) [1]=> int(20) [2]=> int(30) } object(stdClass)#1 (2) { ["foo"]=> array(3) { [0]=> int(10) [1]=> int(20) [2]=> int(30) } ["f"]=> int(42) }

preferences:
298.92 ms | 402 KiB | 330 Q