3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 'abcdefghijklmnopqrstuvwxyz0123456789'; for ($x=0,$r=null;$x<8;$x++) { $r .= substr(0, strlen($a - 1)); } echo $r;
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 TypeError: Unsupported operand types: string - int in /in/DfIPM:6 Stack trace: #0 {main} thrown in /in/DfIPM on line 6
Process exited with code 255.
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33
Warning: A non-numeric value encountered in /in/DfIPM on line 6 Warning: A non-numeric value encountered in /in/DfIPM on line 6 Warning: A non-numeric value encountered in /in/DfIPM on line 6 Warning: A non-numeric value encountered in /in/DfIPM on line 6 Warning: A non-numeric value encountered in /in/DfIPM on line 6 Warning: A non-numeric value encountered in /in/DfIPM on line 6 Warning: A non-numeric value encountered in /in/DfIPM on line 6 Warning: A non-numeric value encountered in /in/DfIPM on line 6
Output for 4.3.0 - 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, 7.0.0 - 7.0.33

preferences:
291.78 ms | 404 KiB | 460 Q