add queue using stack in js

Author: akgmage

Stacks/queue using stack.js

@@ -0,0 +1,45 @@
+// Queue using stack
+class Queue {
+  constructor() {
+    this.enqueueStack = []; // Stack for enqueue operations
+    this.dequeueStack = []; // Stack for dequeue operations
+  }
+
+  enqueue(value) {
+    // Enqueue: Add an element to the back of the queue.
+    this.enqueueStack.push(value);
+  }
+
+  dequeue() {
+    // Dequeue: Remove and return the front element of the queue.
+    // If the dequeue stack is empty, transfer elements from the enqueue stack
+    if (this.dequeueStack.length === 0) {
+      while (this.enqueueStack.length > 0) {
+        // Pop an element from the enqueue stack and push it onto the dequeue stack
+        const element = this.enqueueStack.pop();
+        this.dequeueStack.push(element);
+      }
+    }
+
+    // If the dequeue stack is still empty, the queue is empty
+    if (this.dequeueStack.length === 0) {
+      throw new Error("Queue is empty");
+    }
+
+    // Pop and return the front element from the dequeue stack
+    return this.dequeueStack.pop();
+  }
+}
+
+// Example usage
+const queue = new Queue();
+queue.enqueue(1);
+queue.enqueue(2);
+queue.enqueue(3);
+console.log(queue.dequeue()); // Output: 1
+console.log(queue.dequeue()); // Output: 2
+queue.enqueue(4);
+queue.enqueue(5);
+console.log(queue.dequeue()); // Output: 3
+console.log(queue.dequeue()); // Output: 4
+console.log(queue.dequeue()); // Output: 5