3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array(); $a["key1"] ; echo $a["key1"]; $a["key1"] = 1; echo $a["key1"];
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
Warning: Undefined array key "key1" in /in/VFW2N on line 4 Warning: Undefined array key "key1" in /in/VFW2N on line 6 1
Output for 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, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33
Notice: Undefined index: key1 in /in/VFW2N on line 4 Notice: Undefined index: key1 in /in/VFW2N on line 6 1
Output for 7.3.32 - 7.3.33
1
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
Notice: Undefined index: key1 in /in/VFW2N on line 4 Notice: Undefined index: key1 in /in/VFW2N on line 6 1
preferences:
331.73 ms | 402 KiB | 460 Q