3v4l.org

run code in 300+ PHP versions simultaneously
<?php $s1 = 'toto'; $s2 = 'tata'; var_dump($s1 + $s2); var_dump($s1.$s2); var_dump("{$s1}{$s2}"); var_dump(implode("", array($s1, $s2)));
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 + string in /in/ECa8p:6 Stack trace: #0 {main} thrown in /in/ECa8p on line 6
Process exited with code 255.
Output for 7.1.0 - 7.1.25, 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/ECa8p on line 6 Warning: A non-numeric value encountered in /in/ECa8p on line 6 int(0) string(8) "tototata" string(8) "tototata" string(8) "tototata"
Output for 5.4.2 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20
int(0) string(8) "tototata" string(8) "tototata" string(8) "tototata"

preferences:
189.64 ms | 402 KiB | 241 Q