Instantiate and Destroy Unity3D

Question

I need to instantiate and destroy a prefab on the run. I tried these:

public Transform prefab;     //I attached a prefab in Unity Editor

Object o = Instantiate(prefab);
//using this I cannot get the transform component (I don't know why) so useless

Transform o=(Transform)Instantiate(prefab);
//gives transform and transform component cannot be destroyed

GameObject o=(GameObject)Instantiate(prefab);
//invalid cast

So how to do that?

Answer 1

You don't have to declare your Instance as Object, if you do you get the ancestor object which it has not the transform component.

public GameObject prefab;
GameObject obj = Instantiate(prefab); 

If you want get transform component just type obj.transform.
If you want destroy the object type Destroy(obj);.

Answer 2

gives transform and transform component cannot be destroyed

Destroy the GameObject to which the Transform component is attached to:

GameObject.Destroy(o.gameObject);

Instantiate method returns the same type of the object passed as parameter. Since it's a Transform you can't cast it to GameObject. Try this:

GameObject o=((Transform)Instantiate(prefab)).gameObject;