php判断一个字符串是否为日期格式

<?php
function validateDate($date, $format = 'Y-m-d H:i:s')
{
    $d = DateTime::createFromFormat($format, $date);
    return $d && $d->format($format) == $date;
}

var_dump(validateDate("2021-12-30", "Y-m-d"));
/**
输出:
bool(true)
*/

?>