Learning JavaScript Data Structures and Algorithms - Third Edition

Using the Stack class

In this topic, we will learn how to use the Stack class. The first thing we need to do is instantiate the Stack class we just created. Next, we can verify whether it is empty (the output is true, because we have not added any elements to our stack yet):

    const stack = new Stack();
    console.log(stack.isEmpty()); // outputs true

Next, let's add some elements to it (let's push the numbers 5 and 8; you can add any element type to the stack):

    stack.push(5);
    stack.push(8);

If we call the peek method, it is going to return the element 8, because it was the last element that was added to the stack:

    console.log(stack.peek()); // outputs 8

Let's also add another element:

    stack.push(11);
    console.log(stack.size()); // outputs ...