Queue code added

Author: me-shaon

Data Structure/Queue/Queue.php

@@ -0,0 +1,35 @@
+<?php
+/* Queue Implementation in PHP */
+
+//Queue Class
+class Queue{
+    private $_items = array();
+
+    public function enqueue($value = NULL) {
+        array_unshift($this->_items, $value);
+    }
+
+    public function dequeue() {
+        return array_pop($this->_items);
+    }
+
+    public function peek() {
+        return end($this->_items);
+    }
+
+	public function size() {
+		return count($this->_items);
+	}
+
+	public function isEmpty() {
+		return empty($this->_items);
+	}
+
+    public function printAll() {
+        foreach ($this->_items as $item) {
+            var_dump($item);
+        }
+    }
+}
+
+?>

Data Structure/Queue/test.php

@@ -0,0 +1,27 @@
+<?php
+/***************** Testing the Queue ***************/
+include('Queue.php');
+
+$queue = new Queue();
+$queue->enqueue(10);
+$queue->enqueue(15);
+
+echo $queue->isEmpty() ? 'Empty' : 'Not Empty';
+echo PHP_EOL;
+
+echo $queue->peek();
+echo PHP_EOL;
+
+echo $queue->dequeue();
+echo PHP_EOL;
+
+echo $queue->dequeue();
+echo PHP_EOL;
+
+echo $queue->dequeue();
+echo PHP_EOL;
+
+echo $queue->isEmpty() ? 'Empty' : 'Not Empty';
+echo PHP_EOL;
+
+?>

README.md

@@ -9,7 +9,7 @@
 - [Data Structure](./Data%20Structure/)
   - Linked List
   - [Stack](./Data%20Structure/Stack)
-  - Queue
+  - [Queue](./Data%20Structure/Queue)
   - Binary Search Tree (BST)
   - Heap
   - Hash Table