DateTimeImmutable::add

(PHP 5 >= 5.5.0, PHP 7, PHP 8)

DateTimeImmutable::add Returns a new object, with added amount of days, months, years, hours, minutes and seconds

说明

public DateTimeImmutable::add(DateInterval $interval): DateTimeImmutable

Creates a new DateTimeImmutable object, and adds the specified DateInterval object to this, to represent the new value.

参数

interval

A DateInterval object

返回值

返回带有修改数据的新 DateTimeImmutable 对象。

示例

示例 #1 DateTimeImmutable::add() example

面向对象风格

<?php
$date
= new DateTimeImmutable('2000-01-01');
$newDate = $date->add(new DateInterval('P10D'));
echo
$newDate->format('Y-m-d') . "\n";
?>

示例 #2 Further DateTimeImmutable::add() examples

<?php
$date
= new DateTimeImmutable('2000-01-01');
$newDate = $date->add(new DateInterval('PT10H30S'));
echo
$newDate->format('Y-m-d H:i:s') . "\n";

$date = new DateTimeImmutable('2000-01-01');
$newDate = $date->add(new DateInterval('P7Y5M4DT4H3M2S'));
echo
$newDate->format('Y-m-d H:i:s') . "\n";
?>

以上示例会输出:

2000-01-01 10:00:30
2007-06-05 04:03:02

示例 #3 Beware when adding months

<?php
$date
= new DateTimeImmutable('2000-12-31');
$interval = new DateInterval('P1M');

$newDate1 = $date->add($interval);
echo
$newDate1->format('Y-m-d') . "\n";

$newDate2 = $newDate1->add($interval);
echo
$newDate2->format('Y-m-d') . "\n";
?>

以上示例会输出:

2001-01-31
2001-03-03

参见

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User Contributed Notes 1 note

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-2
Gunnar Bernstein
6 years ago
Please note, add() works a litte different than for DateTime-Objects.

Since DateTimeImmutable is in fact immutable. A line like this will not work:

    $di = new DateTimeImmutable("2018-12-12T10:00:00");
    $di->add(new DateInterval('PT45M')); // $di unchanged !!!

compared to

    $dt = new DateTime("2018-12-12T10:00:00");
    $dt->add(new DateInterval('PT45M')); // added 45 minutes

so you need to write

    $di = new DateTimeImmutable("2018-12-12T10:00:00");
    $di = $di->add(new DateInterval('PT45M')); // $di now changed
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