Java Stack Queue — Free Java Tutorial

TL;DR: Learn Java Stack Queue in Java with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in.

Java Stack Queue in Java

Stack (LIFO — Last In First Out): the last element added is the first removed. Think of a stack of plates. ArrayDeque is the recommended implementation.

Queue (FIFO — First In First Out): the first element added is the first removed. Think of a checkout line. ArrayDeque and LinkedList both implement Queue.

Deque (Double Ended Queue) supports insertion and removal from both ends, making it suitable for both stack and queue patterns.

ArrayDeque is the recommended implementation for both Stack and Queue in modern Java — it is faster than the legacy Stack class (which is synchronized) and LinkedList.

// Stack (LIFO)
Deque<Integer> stack = new ArrayDeque<>();
stack.push(10);   // push to top
stack.pop();      // remove from top
stack.peek();     // view top without removing

// Queue (FIFO)
Queue<String> queue = new ArrayDeque<>();
queue.offer("item");  // enqueue
queue.poll();         // dequeue

Learn Java Stack Queue step by step with Syllab's free interactive Java tutorial — runnable code examples, practice exercises and instant AI feedback, all free with no signup. Explore the full Java course →