3v4l.org

run code in 300+ PHP versions simultaneously
<?php class a{ public $b=['f'=>'c']; } $a=new a; $b='b'; echo $a->b['f']; // without the $ it works $x = $a->$b; // otherwise you need to assign first echo $x['f']; // now it works echo $a->{$b}['f']; // or wrapped in curlies
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
ccc

preferences:
100.63 ms | 1942 KiB | 4 Q