- var_dump: documentation ( source)
- var_export: documentation ( source)
- array_keys: documentation ( source)
<?php
$a = array();
$a["100"] = true;
echo "\$a is an associative map: ";
var_export($a);
$keys = array_keys($a);
echo "It has these keys: ";
var_export($keys);
var_dump( is_string($keys[0]) );