Add queue implementation

Author: kamranahmedse

queue.js

@@ -0,0 +1,30 @@
+class Queue {
+  constructor() {
+    this.items = [];
+  }
+
+  enqueue(item) {
+    this.items.push(item);
+  }
+
+  dequeue() {
+    return this.items.shift();
+  }
+
+  size() {
+    return this.items.length;
+  }
+
+  peek() {
+    return this.items[0];
+  }
+}
+
+const queue = new Queue();
+queue.enqueue(5);  // Queue state: [5]
+queue.enqueue(10); // Queue state: [5, 10]
+queue.enqueue(13); // Queue state: [5, 10, 13]
+console.log(queue.peek()); // Output: 5
+console.log(queue.dequeue()); // Output: 5, Queue State: [10, 13]
+console.log(queue.peek()); // Output: 10
+console.log(queue.size()); // Output: 2

readme.md

@@ -5,8 +5,8 @@ Code accompanying my illustrated Data structures [video series on YouTube](https
 * [What are Data Structures?](https://www.youtube.com/watch?v=9rhT3P1MDHk) — [**Watch Video**](https://www.youtube.com/watch?v=9rhT3P1MDHk)
 * [Array](./array.js) — [**Watch Video**](https://www.youtube.com/watch?v=QJNwK2uJyGs)
 * [Linked List](./linked-list.js) — [**Watch Video**](https://www.youtube.com/watch?v=odW9FU8jPRQ)
-* [Stack](./stack.js) — [Soon on YouTube](https://www.youtube.com/theroadmap?sub_confirmation=1)
-* Queue — [Soon on YouTube](https://www.youtube.com/theroadmap?sub_confirmation=1)
+* [Stack](./stack.js) — [**Watch Video**](https://www.youtube.com/watch?v=I5lq6sCuABE)
+* [Queue](./queue.js) — [Soon on YouTube](https://www.youtube.com/theroadmap?sub_confirmation=1)
 * Heap — [Soon on YouTube](https://www.youtube.com/theroadmap?sub_confirmation=1)
 * Hash Table — [Soon on YouTube](https://www.youtube.com/theroadmap?sub_confirmation=1)
 * Tree — [Soon on YouTube](https://www.youtube.com/theroadmap?sub_confirmation=1)