php的又一深坑

请大家看如下代码，并猜想结果会是什么样的？

 

$arrData = array (                'va_info' => array (array ('position' => 290, 'item' => 70009 ),                                array ('position' => 290, 'item' => 70009 ),                                array ('position' => 290, 'item' => 70009 ),                                array ('position' => 290, 'item' => 70009 ),                                array ('position' => 290, 'item' => 70009 ) ) );foreach ( $arrData['va_info'] as &$data ){        update($arrData);        unset($data);}function update($arrData){        foreach ( $arrData as $col => $value )        {                $arrData [$col] = array ('=', $value );        }        return $arrData;}

结果是foreach的时候arrData变成了reference，于是死循环了