Elevator Emulator Program in Java 

Elevator Emulator is a java program that depicts the functionality of an elevator in a programmatic way.

The elevator starts from ground 1 and welcomes the user with a greeting. It then asks for the destination floor no. and greets accordingly.

Example:

Enter Destination Floor

3

The door is closing…

Going up…2

Going up…3

Hello, opening the door, we are on 3

Enter destination floor

1

Door is closing…

Going down…3

Going down…2

Going down…1

Hello opening the door, we are on 1

Algorithm for simple elevator emulator:

1. First create a source floor variable named n1 and set it to 1.

2. Secondly, make a do-while loop that asks the user to enter the destination floor input named n2.

3. There may be two cases:-

Case 1) Destination floor is greater than source floor

In this case, the elevator has to go upwards. Thus, we will create a for loop which starts from the source floor and ends till destination one. The for loop increments by 1 each time.

Case 2) Destination floor is lesser than source floor

In this case, the elevator has to go downwards. Thus, we will create a for loop which starts from the source floor and ends till destination one. The for loop decrements by 1 each time.

4. We will simply greet the user by specifying that he/she has reached the destination floor.

Program for simple elevator emulator:-

package com.test;
import java.util.Scanner;
public class Elevator
 {
  public static void main(String[] args)
   {
  Scanner sc=new Scanner(System.in);
  int n1=1;
  do
  {
  System.out.println("Enter destination floor");
  System.out.println("Door is closing...");
 int n2=sc.nextInt();
 int i;
 if(n2>n1)
 {
   for( i=n1;i<=n2;i++) System.out.println("Going up..."+i) ;
   i--;
 }
 else
{
  for( i=n1;i>=n2;i--)  System.out.println("Going down..."+i);
  i++;
}
   System.out.println("Hello, opening the door, we are on "+i);
n1=n2;
  }while(true);
}
}

Input:-

Enter Destination Floor

3

Door is closing…

Going up…2

Going up…3

Hello, opening the door, we are on 3

Enter destination floor

1

Door is closing…

Going down…3

Going down…2

Going down…1

Hello, opening the door, we are on 1

Enter destination floor

2

Door is closing…

Going up…1

Going up…2

Hello, opening the door, we are on 2

Enter destination floor

4

Door is closing…

Going up…2

Going up…3

Going up…4

Hello, opening the door, we are on 4