Array Index Out of Range

I’m having an array index out of range problem that I just can’t seem to solve :S Does anyone have an idea? I’ve been looking it over and can’t seem to locate the problem

currentWaypointLocation = -1;

var whichShell = ball.GetComponent("BallController").currentWaypointLocation;
ball.GetComponent("BallController").SetPosition(shells[whichShell].transform.localPosition.x, shells[whichShell].transform.localPosition.z);


code addn

 //Start with the middle one - base all other positions off the middle
	shells[1].transform.localPosition.x = this.transform.localPosition.x;
	shells[1].transform.localPosition.z = this.transform.localPosition.z;
	shells[0].transform.localPosition.x = shells[1].transform.localPosition.x - .30;
	shells[0].transform.localPosition.z = shells[1].transform.localPosition.z;
	shells[2].transform.localPosition.x = shells[1].transform.localPosition.x + .30;
	shells[2].transform.localPosition.z = shells[1].transform.localPosition.z;
	//Starting 'numbers'
	shells[0].GetComponent("ShellController").curPositionNum = 0;
	shells[1].GetComponent("ShellController").curPositionNum = 1;
	shells[2].GetComponent("ShellController").curPositionNum = 2;
	//Set Reference Numbers -- For checking if user selects right shell later
	shells[0].GetComponent("ShellController").shellReference = 0;
	shells[1].GetComponent("ShellController").shellReference = 1;
	shells[2].GetComponent("ShellController").shellReference = 2;
	//Ball Stuff
	ball.GetComponent("BallController").currentWaypointLocation = Random.Range(0,299) % 3; //Pick a position for the ball to start in
	ball.transform.localPosition.x = shells[ ball.GetComponent("BallController").currentWaypointLocation ].transform.localPosition.x; //Set the position of the ball to whichever shell it is attached to
	ball.transform.localPosition.y = shells[ ball.GetComponent("BallController").currentWaypointLocation ].transform.localPosition.y;
	ball.transform.localPosition.z = shells[ ball.GetComponent("BallController").currentWaypointLocation ].transform.localPosition.z;

for( var ii=0; ii < shells.length; ii++ )
		//If we're the first object
		if( shells[ii].GetComponent("ShellController").curPositionNum == whichMove[0] )
			//Set positions, and start moving
			shells[ii].GetComponent("ShellController").localStartPosition = shells[ii].transform.localPosition;
			shells[ii].GetComponent("ShellController").localEndPosition = shellPositionWaypoints[ whichMove[1] ];
			shells[ii].GetComponent("ShellController").endPositionNum = whichMove[1];
		if( shells[ii].GetComponent("ShellController").curPositionNum == whichMove[1] )
			//Set positions, and start moving
			shells[ii].GetComponent("ShellController").localStartPosition = shells[ii].transform.localPosition;
			shells[ii].GetComponent("ShellController").localEndPosition = shellPositionWaypoints[ whichMove[0] ];
			shells[ii].GetComponent("ShellController").endPositionNum = whichMove[0];
	bAllReachedDestination = false; //No more setting coords, for now

//Stop moving shells when we hit the max number of moves
function StopWhenMovesDone() : boolean
	if( curMoveNumber >= numMovesThisRound )
		bRoundOver = true; //Round is over! NO MORE!
		bRoundChoice = true;
		//Make sure to put the Ball under the shell!
		var whichShell = ball.GetComponent("BallController").currentWaypointLocation;
		ball.GetComponent("BallController").SetPosition( shells[whichShell].transform.localPosition.x, shells[whichShell].transform.localPosition.z); //Set new position of whichever shell it's under!
		ball.GetComponent("BallController").Show(); //Make the ball visible again!

You’re not actually showing any of the relevant code where this is used (also, use the code button to format code properly), but you can’t use -1 as an array index.

Your error is that you are passing -1 into an array (currentWaypointLocation = -1)

Arrays can only accept int values in the range [0, arrayLength)

Also, you are calling GetComponent("String") too often. GetComponent is a very slow method, and passing a string to it makes it even slower. If you are calling your function in a tight loop, you will see a major performance drop.

I have edited your code (below) to avoid calling GetComponent more than needed, and to catch the situation where you pass an illegal index. Also, it looks nicer like this.

    currentWaypointLocation = 0;
    var controller : BallController = ball.GetComponent.<BallController>();
    var whichShell : int = controller.currentWaypointLocation;

    if(whichShell < 0 || whichShell >= shells.GetLength()  )
       Debug.Log("ArrayIndexOutOfBounds! Setting to default value...");
       whichShell = 0;

    controller.SetPosition(shells[whichShell].transform.localPosition.x, shells[whichShell].transform.localPosition.z);