how to set parant of game object from code unity code example

Example 1: set parent of gameobject unity

child.transform.SetParent(newParent);

Example 2: how to parent something unity

public GameObject GameObjectYouWantToParent;
public GameObject TheNewParent;

Transform GameObjectsTransform = GameObjectYouWantToParent.transform;
GameObjectsTransform.parent = TheNewParent;