<?php
$config = new Yaf_Config_Simple([
'application' => ['name' => 'MyApp'],
'database' => ['host' => 'localhost'],
]);
var_dump(isset($config['database']));
var_dump($config->offsetExists('database'));
var_dump(isset($config['cache']));
?>
The above example will output
something similar to:
bool(true)
bool(true)
bool(false)