- var_dump: documentation ( source)
- json_last_error_msg: documentation ( source)
- json_last_error: documentation ( source)
- json_encode: documentation ( source)
<?php
$arr = array('recursive');
$arr[] = & $arr;
var_dump(json_encode($arr));
var_dump(json_last_error());
var_dump(PHP_VERSION_ID >= 50500 ? json_last_error_msg() : NULL);