3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a[1]=''; $b = isset($a[1]); $c = isset($a[2]); echo 'a='.$a; echo 'b='.$b;
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.31, 8.2.0 - 8.2.26, 8.3.0 - 8.3.14, 8.4.1 - 8.4.2
Warning: Array to string conversion in /in/ra0l8 on line 6 a=Arrayb=1
Output for 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: Array to string conversion in /in/ra0l8 on line 6 a=Arrayb=1
Output for 7.3.32 - 7.3.33
a=Arrayb=1
preferences:
95.18 ms | 408 KiB | 5 Q