- var_export: documentation ( source)
- array_keys: documentation ( source)
<?php
enum ArrayKeys { case IncludeAll; }
$array = [
'empty' => '',
'enum' => ArrayKeys::IncludeAll,
'zero' => 0,
'one' => 1,
'null' => null,
'false' => false,
'true' => true,
];
var_export(array_keys($array, ArrayKeys::IncludeAll));