Stack in JavaScript

Stacks are a last-in-first-out (LIFO) data structure. This means that the last element added to the stack is the first element to be removed. Stacks are commonly used to implement function calls, backtracking algorithms, and expression evaluation.

class Stack {
  constructor() {
    this.items = [];
  }

  push(item) {
    this.items.push(item);
  }

  pop() {
    return this.items.pop();
  }

  peek() {
    return this.items[this.items.length - 1];
  }

  isEmpty() {
    return this.items.length === 0;
  }
}

const stack = new Stack();

stack.push(1);
stack.push(2);
stack.push(3);

console.log(stack.peek()); // 3
console.log(stack.pop()); // 3
console.log(stack.pop()); // 2
console.log(stack.pop()); // 1