<?php

$queue = new SplQueue();
//push operation
$queue->enqueue(1);
$queue->enqueue(3);
$queue->enqueue(5);

$top = $queue->bottom();
//top is 1
$first = $queue->dequeue();
//first is 1
$second = $queue->dequeue();
//second is 3
$third = $queue->dequeue();
//third is 5

echo "top = ", $top, "\n";
echo "first = ", $first, "\n";
echo "second = ", $second, "\n";
echo "third = ", $third, "\n";