3v4l.org

run code in 300+ PHP versions simultaneously
<?php function myCheck($in) { return @isset($in); } $var1='Something'; $var2='var1'; echo 'Set:' . isset($$var2); $var2='nope'; echo 'Set:' . isset($$var2); $var2='var1'; echo 'Set:' . myCheck($$var2); $var2='nope'; echo 'Set:' . myCheck($$var2); ?>
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
Set:1Set:Set:1 Warning: Undefined variable $nope in /in/MVXAd on line 16 Set:
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 - 7.4.25, 7.4.27 - 7.4.33
Set:1Set:Set:1 Notice: Undefined variable: nope in /in/MVXAd on line 16 Set:
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, 7.3.32 - 7.3.33, 7.4.26
Set:1Set:Set:1Set:

preferences:
312.22 ms | 403 KiB | 460 Q