(PHP 5 >= 5.3.0, PHP 7, PHP 8)
DateTime::getTimestamp -- DateTimeImmutable::getTimestamp -- DateTimeInterface::getTimestamp -- date_timestamp_get — Gets the Unix timestamp
面向对象风格
过程化风格
Gets the Unix timestamp.
此函数没有参数。
Returns the Unix timestamp representing the date.
| 版本 | 说明 |
|---|---|
| 8.0.0 |
These functions no longer return false on failure.
|
Example #1 DateTime::getTimestamp() example
面向对象风格
<?php
$date = new DateTime();
echo $date->getTimestamp();
?>
过程化风格
<?php
$date = date_create();
echo date_timestamp_get($date);
?>
以上例程的输出类似于：
1272509157
Please note that DateTime::gettimestamp() will return an integer, but DateTime::format("U") will return a string.
timestamp must always be typed as int because in PHP, timestamps are integers.
eg:
- strftime ( string $format [, int $timestamp = time() ] ) : string
- time() // return int
- ...
So IMHO, as PHP becomes more and more a typed language, avoid using DateTime::format("U") to avoid this kind of errors "strftime() expects parameter 2 to be int, string given"
In 32-bit system the unix timestamp will overflow if the date goes beyond year 2038 and this method will return false. In 64-bit systems this function will still work as intended. For more information please see http://en.wikipedia.org/wiki/Year_2038_problem.
Note that for dates before the unix epoch getTimestamp() will return false, whereas format("U") will return a negative number.
<?php
$date = new DateTime("1899-12-31");
// "-2209078800"
echo $date->format("U");
// false
echo $date->getTimestamp();
?>