How to find all GameObjects in a parent in shorter code than I figured out

I'm trying to find a way but it seems many Question for GameObject and answer to that points me to Transform

I want GameObject not transform

and my ending doing codes:

 foreach( GameObject GOs in gameObject) {
     Destroy(GOs);
 }

 Assets/Scripts/CreateFloor.cs(164,17): error CS1579: foreach statement cannot operate on variables of type `UnityEngine.GameObject' because it does not contain a definition for `GetEnumerator' or is not accessible

---

 foreach( GameObject GOs in transform) {
     Destroy(GOs);
 }

seems to work fine but when I test it

 InvalidCastException: Cannot cast from source type to destination type.
 CreateFloor.DestroyFloorF () (at Assets/Scripts/CreateFloor.cs:164)
 ShowFloor.OnTriggerExit (UnityEngine.Collider Other) (at Assets/Scripts/ShowFloor.cs:47)

and at last this one seems to be working:

 List<GameObject> children = new List<GameObject>();
 foreach (Transform child in transform) children.Add(child.gameObject);
 for (int i = 0; i < children.Count; i++) {
     Destroy(children[i]);
 }

witch seems to me a bit big and clumsy is this the only way to get rid of children? and I want to destroy them. not deactivate or anything.

[1]: http://answers.unity3d.com/questions/280231/recursively-get-all-children.html

[2]: http://answers.unity3d.com/questions/205391/how-to-get-list-of-child-game-objects.html

[3]: http://answers.unity3d.com/questions/38760/how-to-get-an-array-of-all-children-of-any-type-bu.html