Not all code paths return a value in coroutine

Questions & Answers
1

I made a script that spawns X amount of asteroids over a certain area. After I made the script an error in the console stated that “not all code returns a value”. Here’s my script:

public GameObject asteroid;
public Vector3 spawnValues;
public int asteroidCount;

// Use this for initialization
void Start () 
{
	StartCoroutine (SpawnAsteroids ());
}

// Update is called once per frame
IEnumerator SpawnAsteroids ()
{
	while (asteroidCount <= 30)
	{
		asteroidCount = asteroidCount + 1; 
		Vector3 spawnPosition = new Vector3 (Random.Range (-spawnValues.x, spawnValues.x), spawnValues.y, spawnValues.z);
		Quaternion spawnRotation = Quaternion.identity;
		Instantiate (asteroid, spawnPosition, spawnRotation);
	}
}

}

Thanks in advance :).

2

A coroutine need to have at least one yield statement or it doesn’t count as coroutine. You may want to do either:

 IEnumerator SpawnAsteroids ()
 {
     while (asteroidCount <= 30)
     {
         asteroidCount = asteroidCount + 1; 
         Vector3 spawnPosition = new Vector3 (Random.Range (-spawnValues.x, spawnValues.x), spawnValues.y, spawnValues.z);
         Quaternion spawnRotation = Quaternion.identity;
         Instantiate (asteroid, spawnPosition, spawnRotation);
        yield return null;
     }
 }

this would wait one frame between each asteroid spawn. If you want to wait longer you would do

yield return new WaitForSeconds(5.0f);

instead of

yield return null;

This would wait 5 seconds between each spawn.

3

Thanks @Bunny83 . The error is going, but for some reason none of the asteroids are spawning. Any ideas as to why?