3v4l.org

run code in 300+ PHP versions simultaneously
<?php @json_encode(null); if (function_exists('json_last_error_msg')) { var_dump(json_last_error_msg()); }
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 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
string(8) "No error"
Output for 4.3.0 - 4.3.1, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45
Output for 4.3.2 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6

Process exited with code 255.
preferences:
317.3 ms | 402 KiB | 460 Q