3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a=array(); $a['x']=7; $a['y']=null; echo $a['x']; echo $a['y']; echo $a['z']; ?>
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
7 Warning: Undefined array key "z" in /in/H5EMV on line 7
Output for 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.37, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33
7 Notice: Undefined index: z in /in/H5EMV on line 7
Output for 7.3.32 - 7.3.33
7
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
7 Notice: Undefined index: z in /in/H5EMV on line 7
preferences:
242.93 ms | 402 KiB | 366 Q