Code for Stack Overflow

We've gone over the different aspects of Stack Overflow and observed the attributes attached to the problem using various UML diagrams. Let us now explore the more practical side of things, where we will work on implementing the Stack Overflow network using multiple languages. This is usually the last step in an object-oriented design interview process.

We have chosen the following languages to write the skeleton code of the different classes present in Stack Overflow:

• Java

• C#

• Python

• C++

• JavaScript

Stack Overflow classes#

In this section, we will provide the skeleton code of the classes designed in the class diagram lesson.

Note: For simplicity, we are not defining getter and setter functions. The reader can assume that all class attributes are private and accessed through their respective public getter methods and modified only through their public method functions.

Constants#

The following code provides the definition of the various enums and custom data types being used in the Stack Overflow design:

Note: JavaScript does not support enumerations so we will be using the Object.freeze() method as an alternative that freezes an object and prevents further modifications.

Account#

The Account class refers to an account of a user on Stack Overflow and is responsible for containing their personal details, such as the username, password, etc. It also allows users to reset their existing passwords. The definition of this class is given below:

User, admin, moderator, and guest#

The User class will be a parent class that represents a regular Stack Overflow user. A normal user can also be an Admin and a Moderator. Another actor is represented by the Guest class that refers to a user who can only search and view questions as well as their answers. However, they need to register an account to ask or answer questions. The definition of these classes is provided below:

Question, answer, comment, and bounty#

Stack Overflow users can create and answer questions, upvote and downvote them, and add bounties and comments to questions. The definition of these classes is provided below:

Badge, tag, and tag list#

Users can have badges that act as their reputation awards. Questions can have tags that describe the category that the question falls in. To keep a count of the tags being used, the TagList class is used. The definition of these classes can is provided below:

Notification#

The Notification class is responsible for sending notifications to users about any new messages, comments, posts, or friend requests via either a phone number, or an email. Its definition is provided below:

Search catalog and interface#

The SearchCatalog class contains information on existing questions and answers. It also implements the Search interface class to enable the search functionality based on the given criteria (tags, usernames, and searched keywords). The definition of these two classes is provided below:

Wrapping up#

We've explored the complete design of Stack Overflow in this chapter. We've looked at how Stack Overflow can be visualized using various UML diagrams and designed using object-oriented principles and design patterns.