Code of Elevator System

We’ve discussed different aspects of the elevator 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 elevator 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 elevator control system:

Java
C#
Python
C++
JavaScript

Elevator system classes#

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

Note: For simplicity, we aren’t 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.

Enumerations#

First of all, we will define all the enumerations required in the elevator system. According to the class diagram, there are three enumerations used in the system i.e., ElevatorState, Direction and DoorState. The code to implement these enumerations is as follows:

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.

public abstract class Button {
    private boolean status;
    public pressDown();
    public abstract boolean isPressed();
}
public class DoorButton extends Button {
    public boolean isPressed() {
        // Definition
    }
}
public class HallButton extends Button  {
    private Direction buttonSign;
    public boolean isPressed() {
        // definition
    }
}
public class ElevatorButton extends Button  {
    private int destinationFloorNumber;
    public boolean isPressed() {
        // definition
    }
}