3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $foo = new ArrayObject(); $foo[] = new ArrayObject(); var_dump(json_encode($foo));
based on hdgkb
Output for 5.2.0 - 7.1.0
string(8) "{"0":{}}"
Output for 5.0.0 - 5.1.6
Fatal error: Call to undefined function json_encode() in /in/f4J2T on line 5
Process exited with code 255.
Output for 4.3.2 - 4.4.9
Fatal error: Cannot instantiate non-existent class: arrayobject in /in/f4J2T on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1
Fatal error: Cannot instantiate non-existent class: arrayobject in /in/f4J2T on line 3