3v4l.org

run code in 300+ PHP versions simultaneously
<?php print_r(array( 'JSON_ERROR_NONE' => JSON_ERROR_NONE, 'JSON_ERROR_DEPTH' => JSON_ERROR_DEPTH, 'JSON_ERROR_STATE_MISMATCH' => JSON_ERROR_STATE_MISMATCH, 'JSON_ERROR_CTRL_CHAR' => JSON_ERROR_CTRL_CHAR, 'JSON_ERROR_SYNTAX' => JSON_ERROR_SYNTAX, 'JSON_ERROR_UTF8' => JSON_ERROR_UTF8, 'JSON_ERROR_RECURSION' => JSON_ERROR_RECURSION, 'JSON_ERROR_INF_OR_NAN' => JSON_ERROR_INF_OR_NAN, 'JSON_ERROR_UNSUPPORTED_TYPE' => JSON_ERROR_UNSUPPORTED_TYPE )); $vTest = array("test"=> null); echo json_encode($vTest);

preferences:
65.08 ms | 405 KiB | 5 Q