PHP根据生日计算年龄（周岁）

<?php
/**
* 根据时间戳计算年龄
* @param $birth
* @return mixed
*/
function howOld($birth) {
list($birthYear, $birthMonth, $birthDay) = explode('-', date('Y-m-d', $birth));
list($currentYear, $currentMonth, $currentDay) = explode('-', date('Y-m-d'));
$age = $currentYear - $birthYear - 1;
if($currentMonth > $birthMonth || $currentMonth == $birthMonth && $currentDay >= $birthDay)
$age++;

return $age;
}
?>
4000
>