Your init(elevators, building) function receives an array of elevator objects and a building object. Use methods, properties, and events on each elevator and the building to control the system.

Elevator Methods

elevator.addDestination(...floors)

Append one or more floors to the destination queue. Consecutive duplicates are ignored.

elevator.clearDestination()

Clear all destinations from the queue. The elevator will stop at the next floor and fire 'idle'.

elevator.goToFloor(floorNumber)

Go to a floor immediately — clears the queue and inserts this floor as the sole destination.

elevator.setIndicator(direction)

Set the boarding indicator: "up", "down", "any", or "none". Controls which waiting passengers board when doors open. Default is "any".

elevator.openDoors()

Request the doors to open. Works when idle (opens immediately) or closing (reverses proportionally). Ignored while moving.

Elevator Properties

elevator.currentFloor

The floor the elevator is currently at (integer). While moving, this is the last floor it was at.

elevator.destinationQueue

A copy of the current destination queue (array of floor numbers).

elevator.pressedFloors

A copy of floor numbers pressed inside the elevator by passengers (car call buttons).

elevator.passengerCount

Number of passengers currently in the elevator.

elevator.maxPassengerCount

Maximum passenger capacity of the elevator.

elevator.isFull

Boolean — true when the elevator is at capacity.

Elevator Events

Register listeners with elevator.on(event, callback).

'idle'

Fired when the elevator has no pending destinations and is ready for a new command.

elevator.on('idle', () => { ... })

'floor_button_pressed' → (floorNum)

Fired when a passenger inside the elevator presses a car call button for a floor.

elevator.on('floor_button_pressed', (floorNum) => { ... })

'passing_floor' → (floorNum, direction)

Fired when the elevator passes a floor while moving. direction is "up" or "down". Not fired for the destination floor.

elevator.on('passing_floor', (floorNum, direction) => { ... })

'stopped_at_floor' → (floorNum)

Fired when the elevator arrives at its destination and begins loading/unloading passengers.

elevator.on('stopped_at_floor', (floorNum) => { ... })

'boarding_finished' → (floorNum)

Fired when all passengers have boarded/exited and doors are about to close. Use this to update the indicator or add destinations based on who boarded.

elevator.on('boarding_finished', (floorNum) => { ... })

Building

The building object provides information about hall calls and the building layout.

building.maxFloor

The highest floor number (0-indexed).

building.waitingFloors

Returns { floors: [int], directions: [string] } — parallel arrays of floors with waiting passengers and their requested directions.

building.on('button_pressed', (floor, direction) => { ... })

Fired when a hall call button is pressed at a floor. direction is "up", "down", or "any" (single-button floors).

Logging

Use console.log() to print messages to the Event Log panel.

console.log(...args)

Print a custom message to the Event Log panel. Accepts any number of arguments, which will be joined by spaces.

console.log("current floor:", elevator.currentFloor)