A Queue is a simple data structure where the first item added is the first one
removed, also known as First In First Out (FIFO).
Requirements: You need PHP 7 for the extension and compatibility.
Installation: The easiest way to install the data structure is by using
the PECL extension.
pecl install ds
Syntax:
public Ds\Queue::functionname()
Example: Here’s how to use the
`Ds\Queue::clear()` function in
PHP:
<?php
// Create a new Queue
$q = new \Ds\Queue();
// Add items to the Queue
$q->push("One");
$q->push("Two");
$q->push("Three");
echo "Initial Queue:\n";
// Show the Queue
print_r($q);
// Clear the Queue
$q->clear();
echo "\nQueue after clearing:\n";
print_r($q);
?>
Output:
Initial Queue:
Ds\Queue Object
(
[0] => One
[1] => Two
[2] => Three
)
Queue after clearing:
Ds\Queue Object
(
)
Complete list of data structure DS\Queue:
| Ds\Queue Functions | Description |
|---|---|
| allocate(size) | Allocate memory for the queue to hold a specific number of elements (`size`). This pre-allocates space to potentially avoid performance overhead during insertions or removals. |
| capacity() | Return the current maximum number of elements the queue can hold without needing reallocation. |
| clear() | Remove all elements from the queue. |
| copy() | Create a new queue that is a shallow copy of the original queue. Changes to the original queue will not be reflected in the copy, and vice versa. |
| count() | Return the number of elements currently in the queue. |
| isEmpty() | Check whether the queue is empty (contains no elements). |
| peek() | Return the first element in the queue (same as get(0)). If the queue is empty, it may return an error or null value. |
| pop() | Remove and return the first element from the queue. If the queue is empty, it may return an error or null value. |
| push(value) | Add a new element to the end (back) of the queue. |
| toArray() | Convert the queue to a regular PHP array. The elements will be in the same order they were inserted (First In First Out - FIFO). |