(PHP 5 >= 5.5.0, PHP 7, PHP 8)
DateTimeImmutable::sub — Subtracts an amount of days, months, years, hours, minutes and seconds
Returns a new DateTimeImmutable object, with the specified DateInterval object subtracted from the specified DateTimeImmutable object.
interval
A DateInterval object
返回带有修改数据的新 DateTimeImmutable 对象。
If an unsupported operation is attempted, such as using a
DateInterval object representing relative time
specifications such as next weekday, a
DateInvalidOperationException is thrown.
| 版本 | 说明 |
|---|---|
| 8.3.0 | Now throws a DateInvalidOperationException instead of a warning when an unsupported operation is attempted. |
示例 #1 DateTimeImmutable::sub() example
面向对象风格
<?php
$date = new DateTimeImmutable('2000-01-20');
$newDate = $date->sub(new DateInterval('P10D'));
echo $newDate->format('Y-m-d') . "\n";
?>以上示例会输出：
2000-01-10
示例 #2 Further DateTimeImmutable::sub() examples
<?php
$date = new DateTimeImmutable('2000-01-20');
$newDate = $date->sub(new DateInterval('PT10H30S'));
echo $newDate->format('Y-m-d H:i:s') . "\n";
$date = new DateTimeImmutable('2000-01-20');
$newDate = $date->sub(new DateInterval('P7Y5M4DT4H3M2S'));
echo $newDate->format('Y-m-d H:i:s') . "\n";
?>以上示例会输出：
2000-01-19 13:59:30 1992-08-15 19:56:58
示例 #3 Beware when subtracting months
<?php
$date = new DateTimeImmutable('2001-04-30');
$interval = new DateInterval('P1M');
$newDate1 = $date->sub($interval);
echo $newDate1->format('Y-m-d') . "\n";
$newDate2 = $newDate1->sub($interval);
echo $newDate2->format('Y-m-d') . "\n";
?>以上示例会输出：
2001-03-30 2001-03-02