3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $a = array(1, 2); $b = array(&$a); $a[] = $b; var_dump(json_encode($a)); echo json_last_error();
based on lpAiD
Output for 5.5.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
bool(false) 6
Output for 5.3.0 - 5.4.45
Warning: json_encode(): recursion detected in /in/FV0GO on line 7 string(18) "[1,2,[[1,2,null]]]" 0
Output for 5.2.0 - 5.2.17
Warning: json_encode(): recursion detected in /in/FV0GO on line 7 string(18) "[1,2,[[1,2,null]]]" Fatal error: Call to undefined function json_last_error() in /in/FV0GO on line 8
Process exited with code 255.
Output for 5.0.0 - 5.1.6
Fatal error: Call to undefined function json_encode() in /in/FV0GO on line 7
Process exited with code 255.
Output for 4.4.5 - 4.4.9
Fatal error: Call to undefined function: json_encode() in /in/FV0GO on line 7
Process exited with code 255.
Output for 4.3.2 - 4.4.4
Fatal error: Call to undefined function: json_encode() in /in/FV0GO on line 7
Process exited with code 255.
Output for 4.3.0 - 4.3.1
Fatal error: Call to undefined function: json_encode() in /in/FV0GO on line 7