3v4l.org

run code in 300+ PHP versions simultaneously
<?php var_dump(json_decode(<<<JSON { "CORS_ALLOW_ORIGIN": "^https?://localhost\\\\(:[0-9]+\\\\)?$" } JSON , true)); var_dump(json_last_error_msg());
Output for 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 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
array(1) { ["CORS_ALLOW_ORIGIN"]=> string(32) "^https?://localhost\(:[0-9]+\)?$" } string(8) "No error"
preferences:
154.03 ms | 408 KiB | 5 Q