3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 0; $a[3] = "hello!"; var_dump(a); $b = false; $b[3] = "hello!"; var_dump(b);
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Fatal error: Uncaught Error: Cannot use a scalar value as an array in /in/E7hXD:4 Stack trace: #0 {main} thrown in /in/E7hXD on line 4
Process exited with code 255.
Output for 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33
Warning: Cannot use a scalar value as an array in /in/E7hXD on line 4 Warning: Use of undefined constant a - assumed 'a' (this will throw an Error in a future version of PHP) in /in/E7hXD on line 5 string(1) "a" Warning: Use of undefined constant b - assumed 'b' (this will throw an Error in a future version of PHP) in /in/E7hXD on line 9 string(1) "b"
Output for 5.4.2 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20
Warning: Cannot use a scalar value as an array in /in/E7hXD on line 4 Notice: Use of undefined constant a - assumed 'a' in /in/E7hXD on line 5 string(1) "a" Notice: Use of undefined constant b - assumed 'b' in /in/E7hXD on line 9 string(1) "b"

preferences:
194.64 ms | 403 KiB | 227 Q