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    SplQueue::dequeue

    (PHP 5 >= 5.3.0, PHP 7, PHP 8)

    SplQueue::dequeue — キューからノードを取り出す

    説明

    public SplQueue::dequeue(): mixed

    value をキューの先頭から取り出します。

    注意:

    SplQueue::dequeue() は SplDoublyLinkedList::shift() のエイリアスです。

    パラメータ

    この関数にはパラメータはありません。

    戻り値

    キューから取り出したノードの値を返します。

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    User Contributed Notes 4 notes

    up
    9
    xuecan at gmail dot com
    14 years ago
    If the queue is empty, dequeue() will raise an 'RuntimeException' with message 'Can't shift from an empty datastructure'.
    up
    4
    mark at bull-roarer dot com
    11 years ago
    I just thought this was a fun and interesting way for lining up method calls and then calling them back-to-back. Might be useful as a basis for a transactional execution class or something.

    <?php
    $q     = new SplQueue();
    $q->setIteratorMode(SplQueue::IT_MODE_DELETE);

    $q->enqueue(array("FooBar", "foo"));
    $q->enqueue(array("FooBar", "bar"));
    $q->enqueue(array("FooBar", "msg", "Hi there!"));

    foreach (    $q as $task) {
    if (    count($task) > 2) {
    list(    $class, $method, $args) = $task;
    $class::$method($args);
    } else {
    list(    $class, $method) = $task;
    $class::$method();
    }
    }

    class     FooBar {
    public static function     foo() {
    echo     "FooBar::foo() called.\n";
    }
    public static function     bar() {
    echo     "FooBar::bar() called.\n";
    }
    public static function     msg($msg) {
    echo     "$msg\n";
    }
    }
    ?>

    Results:
    FooBar::foo() called.
    FooBar::bar() called.
    Hi there!
    up
    3
    andresdzphp at php dot net
    13 years ago
    <?php
    $q     = new SplQueue();
    $q->setIteratorMode(SplQueue::IT_MODE_DELETE);
    $q->enqueue('item 1');
    $q->enqueue('item 2');
    $q->enqueue('item 3');

    $q->dequeue();
    $q->dequeue();

    foreach (    $q as $item) {
    echo     $item;
    }

    //Result: item 3

    $q->dequeue(); //Fatal error: Uncaught exception 'RuntimeException'
    //with message 'Can't shift from an empty datastructure'
    ?>
    up
    0
    mark at bull-roarer dot com
    11 years ago
    I just thought this was a fun and interesting way for lining up method calls and then calling them back-to-back. Might be useful as a basis for a transactional execution class or something.

    <?php
    $q     = new SplQueue();
    $q->setIteratorMode(SplQueue::IT_MODE_DELETE);

    $q->enqueue(array("FooBar", "foo"));
    $q->enqueue(array("FooBar", "bar"));
    $q->enqueue(array("FooBar", "msg", "Hi there!"));

    foreach (    $q as $task) {
    if (    count($task) > 2) {
    list(    $class, $method, $args) = $task;
    $class::$method($args);
    } else {
    list(    $class, $method) = $task;
    $class::$method();
    }
    }

    class     FooBar {
    public static function     foo() {
    echo     "FooBar::foo() called.\n";
    }
    public static function     bar() {
    echo     "FooBar::bar() called.\n";
    }
    public static function     msg($msg) {
    echo     "$msg\n";
    }
    }
    ?>

    Results:
    FooBar::foo() called.
    FooBar::bar() called.
    Hi there!
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