throw new RunTimeException('Stack is empty!');
} else {
// pop item from the start of the array
return array_shift($this->stack);
}
}
public function top()
{
return current($this->stack);
}
public function isEmpty()
{
return empty($this->stack);
}
}
$myBooks = new ReadingList();
// add some items to the stack
$myBooks->push('A Dream of Spring');
$myBooks->push('The Winds of Winter');
$myBooks->push('A Dance with Dragons');
$myBooks->push('A Feast for Crows');
$myBooks->push('A Storm of Swords');
$myBooks->push('A Clash of Kings');
$myBooks->push('A Game of Thrones');
// removing items from the stack
echo $myBooks->pop() . "\n";
// outputs 'A Game of Thrones'
echo $myBooks->pop() . "\n";
// outputs 'A Clash of Kings'
echo $myBooks->pop() . "\n";
// outputs 'A Storm of Swords'
<?php
class ReadingList extends SplStack
{
}
$myBooks = new ReadingList();
// add some items to the stack
$myBooks->push('A Dream of Spring');
$myBooks->push('The Winds of Winter');
$myBooks->push('A Dance with Dragons');
$myBooks->push('A Feast for Crows');
$myBooks->push('A Storm of Swords');
$myBooks->push('A Clash of Kings');
$myBooks->push('A Game of Thrones');
// normal top-down traversal (last item shown first)
// default traversal mode for a stack
$myBooks->setIteratorMode(SplDoublyLinkedList::IT_MODE_LIFO | SplDoublyLinkedList::IT_MODE_KEEP);
echo "Traversing Top-Down...\n";
foreach ($myBooks as $book) {
echo $book . "\n";
}
// bottom-up traversal (first item inserted shown first)
$myBooks->setIteratorMode(SplDoublyLinkedList::IT_MODE_FIFO | SplDoublyLinkedList::IT_MODE_KEEP);
echo "\nTraversing Bottom-Up...\n";
foreach ($myBooks as $book) {
echo $book . "\n";
}
