Operator '+' cannot be used with a left hand side of type 'Object' and a right hand side of type 'float'

Questions & Answers
1

I’m trying to create an infinite runner and am seeing if I can translate some of the C# codes into Javascript. I’ve currently run into a problem that I can’t really seem to fix. I get that error for this line of code (also listed below):

  //This way gets the point at which you should add the room, so that it started straight after the last room.
    // Operator '+' cannot be used with a left hand side of type 'Object' and a right hand side of type 'float'.
    var roomCenter: float = farhtestRoomEndX + roomWidth * 0.5f;

I don’t understand why that is? Is it how I’m declaring the variable farhtestRoomEndX? (it was already declared as a float in the line just above it).

For reference, this is the c# line: float roomCenter = farhtestRoomEndX + roomWidth * 0.5f;

And the whole code I’ve written so far

#pragma strict

var availableRooms: GameObject[]; //this will contain an array of prefabs which the script will generate
var currentRooms: GameObject[]; //this will check our current room, when it should create new rooms & when to delete old rooms
private var screenWidthInPoints: float; //will cache the screen size in points to determine next rooms & delete old rooms
var farhtestRoomEndX: float;

function Start()
{
	//calculate the size of the screen in points
	var height: float = 2.0f * Camera.main.orthographicSize;
	screenWidthInPoints = height * Camera.main.aspect;
}

function AddRoom(farhtestRoomEndX)
{
    //Picks a random index of the room type (Prefab) to generate.
    var randomRoomIndex: int = Random.Range(0, availableRooms.Length);
 
    //Creates a room object from the array of available rooms using the random index above.
    var room: GameObject; 
    room = Instantiate(availableRooms[randomRoomIndex]);
 
    //Get the size of the floor inside the room, which is equal to the room’s width.
    var roomWidth: float = room.transform.FindChild("floor").localScale.x;
 
    //This way gets the point at which you should add the room, so that it started straight after the last room.
    // Operator '+' cannot be used with a left hand side of type 'Object' and a right hand side of type 'float'.
    var roomCenter: float = farhtestRoomEndX + roomWidth * 0.5f;
 
    //This sets the position of the room. You need to change only the x-coordinate since all rooms have the same y and z coordinates equal to zero.
    room.transform.position = new Vector3(roomCenter, 0, 0);
 
    //add the room to the list of current rooms. 
    currentRooms.Add(room);
2

Your code is confusing. You declare:

 var farhtestRoomEndX: float;

…at the top of the file, but you use the same name for the parameter here:

  function AddRoom(farhtestRoomEndX)

You fix the immediate problem by change the function declaration to:

  function AddRoom(farhtestRoomEndX : float)

…but you might want to change the name of the parameter, or don’t use a parameter if you want to use the variable.

Also built-in arrays don’t have an Add() function. Consider using a generic List.

3

I think I solved it! Rather than keeping the built in array I made it into a (normal?) javascript array

ar currentRooms = new ArrayList();

and kept the same line of code of the add() function.