We’ve reviewed different aspects of the car rental system and observed the attributes attached to the problem using various UML diagrams. Let’s explore the more practical side of things, where we will work on implementing the car rental system 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 the car rental system:

  • Java

  • C#

  • Python

  • C++

  • JavaScript

Car rental system 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 methods function.


First, we will define all the enumerationsA special data type which contains a set of predefined constants. required in the car rental system. According to the class diagram, there are seven enumerations used in the system, i.e., VehicleStatus, AccountStatus, ReservationStatus, PaymentStatus, VanType, CarType, and VehicleLogType. The code to implement these enumerations is as follows:

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

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