Stacks

We will need a basic understanding of how stacks work to understand the next section. If you have never heard of a stack data structure, I will summarize it in this section. I still encourage you to do more thorough research before continuing, as you will need it in your programming career.

Imagine a stack like a JavaScript array whose elements are not accessible. Suppose stack S is given. You can only execute the following operations on it:

• S.length: checks the length of the stack
• S.push(element): pushes an element to the stack
• S.pop(): removes the top element from the stack and returns it

You can neither access nor modify any elements of the stack other than the element at position S.length - 1. In Exercise 1, you will have a chance to implement a stack in ES6.

There are two types of memory available to you: the stack and the heap. The heap is used for dynamic memory allocation, while the stack is used for static memory allocation. Accessing the stack is very fast, but the size of the stack is fixed.

A stack frame is created for the global scope. Then, for each function call, another stack frame is added to the top. These frames stack on top of each other.

When executing JavaScript code, you get a stack with limited size to work with. To get an idea of typical stack size limits in practice, look at this page.

Regardless of the browser, iterating from zero to a million in a for loop is an easy task.