If the queue is empty, dequeue() will raise an 'RuntimeException' with message 'Can't shift from an empty datastructure'.(PHP 5 >= 5.3.0, PHP 7, PHP 8)
SplQueue::dequeue — Remove um nó da fila
   Remove o value do topo da fila.
  
Nota:
SplQueue::dequeue() é um sinônimo de SplDoublyLinkedList::shift().
Esta função não possui parâmetros.
O valor do nó retirado da fila.
If the queue is empty, dequeue() will raise an 'RuntimeException' with message 'Can't shift from an empty datastructure'.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!<?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'
?>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!