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Hi All.

I'm having some trouble adding and especially retrieving GameObjects from an array. Here is a code sample:

var balls = new Array();

function Start() {

// Instantiate ball for test-purpose
var newBall : GameObject = GameObject.Instantiate(ballPrefab,Vector3(10.0,0.0,10.0),Quaternion.identity) as GameObject;
balls.Add(newBall);

}

function findClosestBall(ball_x : int, ball_y : int) : GameObject {

for (var i=0; balls.length; i++){
    var ball : GameObject = balls[i] as GameObject; // THIS MAKES ERROR
    var ballVector : Vector3 = (ball.transform.position);
}

return null;

}

The error I'm getting is: NullReferenceException: Object reference not set to an instance of an object

What am I doing wrong? What is the correct way to store an array of GameObjects?

Thanks, Jonas

Answer 1

Problem is solved. Answer can be found at http://forum.unity3d.com/viewtopic.php?t=49078

In short, here is the code:

var balls : ArrayList;

function Start() { balls = new ArrayList();

// Instantiate ball for test-purpose var newBall = Instantiate(ballPrefab,Vector3(10.0,0.0,10.0),Quaternion.identity); balls.Add(newBall.gameObject); // Notice .gameObject }

function findClosestBall(ball_x : int, ball_y : int) : GameObject {

var closestBall : GameObject; var shortestDistance : float = 9999; var ballPos : Vector3; var coordinatePos : Vector3; var distanceVector : Vector3;

for(var ball : GameObject in balls){ ballPos = ball.transform.position; coordinatePos = Vector3(ball_x, GameController.y_height, ball_y); distanceVector = ballPos - coordinatePos;

  if (distanceVector.magnitude < shortestDistance){ 
     closestBall = ball; 
     shortestDistance = distanceVector.magnitude; 
  }

} return closestBall; }

Answer 2

0

your for statement has an error. It says:

for (var i=0; balls.length; i++) {

when it should say:

for (var i=0; i < balls.length; i++){

answered Apr 09 '10 at 09:55 AM

duck ♦♦
41k ● 92 ● 148 ● 415

Yeah of course. That's not the error though.

Apr 09 '10 at 10:37 AM Jonas

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