run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = json_encode('wrong json'); /*if ('50500' <= PHP_VERSION_ID) { var_dump(json_last_error_msg()); }*/ switch (json_last_error()) { case JSON_ERROR_DEPTH: $error = 'Maximum stack depth exceeded'; break; case JSON_ERROR_STATE_MISMATCH: $error = 'Underflow or the modes mismatch'; break; case JSON_ERROR_CTRL_CHAR: $error = 'Unexpected control character found'; break; case JSON_ERROR_SYNTAX: $error = 'Syntax error, malformed JSON'; break; case JSON_ERROR_UTF8: $error = 'Malformed UTF-8 characters, possibly incorrectly encoded'; break; default: $error = 'Unknown error'; break; } var_dump($error);
based on vDss3

Shows result from various feature-branches currently under review from the php developers. Contact me to have additional branches featured.

Output for Typed properties v2
string(13) "Unknown error"
Output for Array change keys
string(13) "Unknown error"
Output for Lexical anon
string(13) "Unknown error"

Archived branches

Once feature-branches are merged or declined, they are no longer available. Their functionality (when merged) can be viewed from the main output page