``` // 根据生日计算年龄 function age($date){ $year_diff = ''; $time = strtotime($date); if(FALSE === $time){ return ''; } $date = date('Y-m-d', $time); list($year,$month,$day) = explode("-",$date); $year_diff = date("Y") – $year; $month_diff = date("m") – $month; $day_diff = date("d") – $day; if ($day_diff < 0 || $month_diff < 0) $year_diff–; return $year_diff; } ```