IntlCalendar::clear

例1 IntlCalendar::clear() examples
 <?phpini_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"; 
上の例の出力は以下となります。
 
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