IntlCalendar::clear

(PHP 5 >= 5.5.0, PHP 7, PHP 8, PECL >= 3.0.0a1)

IntlCalendar::clear — Clear a field or all fields

说明

面向对象风格

public IntlCalendar::clear(?int $field = null): true

过程化风格

intlcal_clear(IntlCalendar $calendar, ?int $field = null): true

Clears either all of the fields or a specific field. A cleared field is marked as unset, giving it the lowest priority against overlapping fields or even default values when calculating the time. Additionally, its value is set to 0, though given the fieldʼs low priority, its value may have been internally set to another value by the time the field has finished been queried.

参数

calendar: IntlCalendar 实例。
field: One of the IntlCalendar date/time field constants. These are integer values between 0 and IntlCalendar::FIELD_COUNT.

返回值

总是返回 true。

更新日志

版本	说明
8.2.0	现在返回类型为 `true`；之前是 bool。

示例

示例 #1 IntlCalendar::clear() examples

<?php
ini_set('intl.default_locale', 'es_ES');
ini_set('date.timezone', 'UTC');

$fields = array(
    'FIELD_ERA'                  => 0,
    'FIELD_YEAR'                 => 1,
    'FIELD_MONTH'                => 2,
    'FIELD_WEEK_OF_YEAR'         => 3,
    'FIELD_WEEK_OF_MONTH'        => 4,
    'FIELD_DATE'                 => 5,
    'FIELD_DAY_OF_YEAR'          => 6,
    'FIELD_DAY_OF_WEEK'          => 7,
    'FIELD_DAY_OF_WEEK_IN_MONTH' => 8,
    'FIELD_AM_PM'                => 9,
    'FIELD_HOUR'                 => 10,
    'FIELD_HOUR_OF_DAY'          => 11,
    'FIELD_MINUTE'               => 12,
    'FIELD_SECOND'               => 13,
    'FIELD_MILLISECOND'          => 14,
    'FIELD_ZONE_OFFSET'          => 15,
    'FIELD_DST_OFFSET'           => 16,
    'FIELD_YEAR_WOY'             => 17,
    'FIELD_DOW_LOCAL'            => 18,
    'FIELD_EXTENDED_YEAR'        => 19,
    'FIELD_JULIAN_DAY'           => 20,
    'FIELD_MILLISECONDS_IN_DAY'  => 21,
    'FIELD_IS_LEAP_MONTH'        => 22,
    'FIELD_FIELD_COUNT'          => 23,
);
function getSetFields(IntlCalendar $cal) {
    global $fields;
    $ret = array();
    foreach ($fields as $name => $value) {
        if ($cal->isSet($value)) {
            $ret[] = $name;
        }
    }
    return $ret;
}

$cal = new IntlGregorianCalendar(2013, 2 /* March */, 15);
echo "After GregorianCalendar creation\n";
print_r(getSetFields($cal));
echo "\n";

echo IntlDateFormatter::formatObject($cal), "\n";
echo "After the formatter requested the extended year\n";
print_r(getSetFields($cal));
echo "\n";

$cal->clear(IntlCalendar::FIELD_YEAR);
echo "After the year has been cleared, the date stays the same\n";
echo IntlDateFormatter::formatObject($cal), "\n";
echo "because FIELD_EXTENDED_YEAR is still set\n";
print_r(getSetFields($cal));
echo "\n";

var_dump($cal->clear(IntlCalendar::FIELD_EXTENDED_YEAR));
echo "After the extended year has been cleared\n";
print_r(getSetFields($cal));
echo IntlDateFormatter::formatObject($cal), "\n";
echo "\n";

echo "After the fields are recalculated,\n"
        . " extended year is set again (to 1970)\n";
print_r(getSetFields($cal));
echo "\n";

$cal->clear();
echo "After calling variant with no arguments\n";
print_r(getSetFields($cal));
echo IntlDateFormatter::formatObject($cal), "\n";

以上示例会输出：

After GregorianCalendar creation
Array
(
    [0] => FIELD_ERA
    [1] => FIELD_YEAR
    [2] => FIELD_MONTH
    [3] => FIELD_DATE
)

15/03/2013 00:00:00
After the formatter requested the extended year
Array
(
    [0] => FIELD_ERA
    [1] => FIELD_YEAR
    [2] => FIELD_MONTH
    [3] => FIELD_DATE
    [4] => FIELD_EXTENDED_YEAR
)

After the year has been cleared, the date stays the same
15/03/2013 00:00:00
because FIELD_EXTENDED_YEAR is still set
Array
(
    [0] => FIELD_ERA
    [1] => FIELD_MONTH
    [2] => FIELD_DATE
    [3] => FIELD_EXTENDED_YEAR
)

bool(true)
After the extended year has been cleared
Array
(
    [0] => FIELD_ERA
    [1] => FIELD_MONTH
    [2] => FIELD_DATE
)
15/03/1970 00:00:00

After the fields are recalculated,
 extended year is set again (to 1970)
Array
(
    [0] => FIELD_ERA
    [1] => FIELD_MONTH
    [2] => FIELD_DATE
    [3] => FIELD_EXTENDED_YEAR
)

After calling variant with no arguments
Array
(
)
01/01/1970 00:00:00