Clear a field or all fields

# IntlCalendar::clear

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

IntlCalendar::clear — Clear a field or all fields

### 説明

オブジェクト指向型

public IntlCalendar::clear ([ int `$field` = NULL ] ) : bool

手続き型

intlcal_clear ( IntlCalendar `$cal` [, int `$field` = NULL ] ) : bool

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.

### パラメータ

`cal`

  The IntlCalendar resource.

`field`

  IntlCalendar の日付/時刻 フィールド定数 のいずれか。 0 から `IntlCalendar::FIELD_COUNT` までの間の整数値です。

### 返り値

Returns `TRUE` on success失敗した場合に `FALSE` を返します. Failure can only occur is invalid arguments are provided.

### 例

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";`

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