return false; } } public function isFull() { } } $q = new Queue(5); // instantiates the Queue class with a maxSize attribute of 5 $q->isEmpty(); // returns true $q->enqueue(100); // Queue: 100 $q->rear(); // returns 100 $q->front(); // returns 100 $q->enqueue(20); // Queue: 100, 20 $q->enqueue(2); // Queue: 100, 20, 2 $q->dequeue(); // Queue: 20, 2 $q->enqueue(500); // Queue: 20, 2, 500 $q->enqueue(12); // Queue: 20, 2, 500, 12 $q->enqueue(30); // Queue: 20, 2, 500, 12, 30 $q->isFull(); // returns true
*/ public function enqueue($el) { array_push($this->_queue, $el); } /** * Dequeue the front element from the queue. * * @return mixed $element. */ public function dequeue() { if ($this->front() !== null) { return array_shift($this->_queue); } return null; } } // Example usage: $queue = new Queue(); $queue->enqueue("Element"); $queue->enqueue(23); $queue->enqueue(array(3, 4, 6)); while (!$queue->is_empty()) { echo "The front element is now : \n"; var_dump($queue->front()); echo "\n"; $queue->dequeue(); } // Outputs NULL var_dump($queue->front());
while ($current) { echo $current->value . ", "; $current = $current->next; } echo "<br>"; } } $q = new Queue(5); // instantiates the Queue class with a maxSize attribute of 5 echo $q->isEmpty() . "<br>"; // returns true $q->enqueue(100); // Queue: 100 echo $q->rear() . "<br>"; // returns 100 echo $q->front() . "<br>"; // returns 100 $q->enqueue(20); // Queue: 100, 20 $q->enqueue(2); // Queue: 100, 20, 2 $q->dequeue(); // Queue: 20, 2 $q->enqueue(500); // Queue: 20, 2, 500 $q->enqueue(12); // Queue: 20, 2, 500, 12 $q->enqueue(30); // Queue: 20, 2, 500, 12, 30 echo $q->isFull() . "<br>"; // returns true