(PHP 5 >= 5.5.0, PHP 7, PHP 8, PECL >= 3.0.0a1)
IntlCalendar::roll — Add value to field without carrying into more significant fields
面向对象风格
过程化风格
Adds a (signed) amount to a field. The difference with respect to IntlCalendar::add() is that when the field value overflows, it does not carry into more significant fields.
calendarIntlCalendar 实例。
field
One of the IntlCalendar date/time field constants. These are integer
values between 0 and
IntlCalendar::FIELD_COUNT.
value
The (signed) amount to add to the field, true for rolling up (adding
1), or false for rolling down (subtracting
1).
示例 #1 IntlCalendar::roll()
<?php
ini_set('date.timezone', 'Europe/Lisbon');
ini_set('intl.default_locale', 'pt_PT');
$cal = new IntlGregorianCalendar(2013, 5 /* June */, 30);
$cal->add(IntlCalendar::FIELD_DAY_OF_MONTH, 1);
var_dump(IntlDateFormatter::formatObject($cal)); // "01/07/2013, 00:00:00"
$cal->set(2013, 5 /* June */, 30);
$cal->roll(IntlCalendar::FIELD_DAY_OF_MONTH, true); // roll up, same as rolling +1
var_dump(IntlDateFormatter::formatObject($cal)); // "01/06/2013, 00:00:00"以上示例会输出：
string(20) "01/07/2013, 00:00:00" string(20) "01/06/2013, 00:00:00"