Class Diagram for Facebook

Learn to create a class diagram for Facebook using the bottom-up approach.

We'll cover the following...

In this lesson, we’ll identify and design the classes, abstract classes, and interfaces based on the requirements we previously gathered from the interviewer in our Facebook social network system.

Components of Facebook

As mentioned, we will design the Facebook social network using a bottom-up approach.

Person

The Person class contains details derived from the User class, such as name, address, phone number, and email.

User

The User class is Facebook’s main class responsible for various operations, such as sending messages or friend requests to other users, creating or joining groups or pages, and numerous others.

The class diagram of these two classes is provided below:

Note: The User class contains various methods representing user interactions and functionalities within the system. For brevity, only a subset of these methods is shown here.

The class diagram of the Person and User classes
The class diagram of the Person and User classes

Profile

The Profile class contains a Facebook user’s personal information, such as their profile and cover pictures, work and education details, and a list of places they’ve visited.

The visual representation of the Profile class is given below:

The class diagram of the Profile class
The class diagram of the Profile class

Work, education, and places

The Work, Education, and Places classes are used to provide relevant information and are involved in the Profile class.

The class representation of these classes is given below:

The class diagram of the Work, Education, and Places classes
The class diagram of the Work, Education, and Places classes

Page

The Page class represents a page on the Facebook platform. It contains the name, description, likes count, and a particular ID to uniquely identify the page.

The UML representation of the class is shown below:

The class diagram of the Page class
The class diagram of the Page class

Group

The Group class represents a particular group on the Facebook platform. It will contain the name, description, total users, and a unique ID to uniquely identify the group. In addition, it will have methods for adding new users and updating the group’s description.

The UML representation of the class is shown below: ...