public function test_index_2() { $name = array('name' => 'John Doe', 'first' => 'John', 'middle' => 'M', 'last' => 'Doe', 'title' => 'Dr.', 'suffix' => 'Jr.'); $ret = Enumerator::index_($name, function ($key, &$value) { return strpos($value, '.') !== false; // Has a decimal }); $this->assertEquals('title', $ret); }