A Common-Sense Guide to Data Structures and Algorithms in JavaScript, Volume 1

Abstract Data Types

Most programming languages don’t come with the stack as a built-in data type or class. Instead, it’s up to you to implement it yourself. This is a stark contrast with arrays, which are available in most languages.

To create a stack, then, you generally have to use one of the built-in data structures to hold the data. Here’s one way to implement a stack using JavaScript, which uses an array under the hood:

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

  push(element) {
    this.data.push(element);
  }

  pop() {
    if (this.data.length > 0) {
      return this.data.pop();
    } else {
      return null;
    }
  }

  read() {
    if (this.data.length > 0) {
      return this.data[this.data.length - 1]; ...