PHP DataStructures

Data structure is a way of storing and organizing data in a computer so that it can be used efficiently. It provide a efficient way to manage large amounts of data efficiently, such as large databases and Internet indexing services.

SPL provides a following set of standard datastructures.
SplDoublyLinkedList: The SplDoublyLinkedList class provides the main functionalities of a doubly linked list.

SplStack
The SplStack class provides the main functionalities of a stack implemented using a doubly linked list.

SplQueue
The SplQueue class provides the main functionalities of a queue implemented using a doubly linked list.
See Example

echo "Create Object of SplQueue:";
$obj = new SplQueue();

echo "
Check for Queue, is it Empty:";
if($obj->isEmpty())
{
    $obj->enqueue("Simple");
    $obj->enqueue("Example");
    $obj->enqueue("Of");
    $obj->enqueue("PHP");
}
echo "View queue:";
print_r($obj);
if(! $obj->offsetExists(4))
{
    $obj->enqueue(10);
}
print_r($obj);
echo "
";
echo "
Get the value of the offset at 3 ";
if($obj->offsetGet(3))
{
    echo $obj->offsetGet(3);
   
    echo "
Resetting the value of a node:";
    $obj->offsetSet(4,6);
}

SplHeap The SplHeap class provides the main functionalities of a Heap. Heaps are crucial in several efficient graph algorithms such as Dijkstra's algorithm, and in the sorting algorithm heapsort.

SplMaxHeap The SplMaxHeap class provides the main functionalities of a heap, keeping the maximum on the top.

SplMinHeap The SplMinHeap class provides the main functionalities of a heap, keeping the minimum on the top.

SplPriorityQueue The SplPriorityQueue class provides the main functionalists of an functionalists of an prioritized queue, implemented using a max heap.

SplFixedArray The SplFixedArray class provides the main functionalities of array. The main differences between a SplFixedArray and a normal PHP array is that the SplFixedArray is of fixed length and allows only integers within the range as indexes. The advantage is that it allows a faster array implementation. See Example Below

$array = new SplFixedArray(5);
$array[1] = 2;
$array[4] = "foo";
var_dump($array[0]); // NULL
var_dump($array[1]); // int(2)

var_dump($array["5"]); // Fatal error: Uncaught exception 'RuntimeException' with message 'Index invalid or out of range'

SplObjectStorage The SplObjectStorage class provides a map from objects to data or, by ignoring data, an object set. This dual purpose can be useful in many cases involving the need to uniquely identify objects.

Web Technology Experts Notes

Thursday 5 June 2014