Undo.AddComponent

public static Component AddComponent(GameObject gameObject, Type type);

Parameters

gameObject		The game object you want to add the component to.
type		The type of component you want to add.

Component The newly added component.

Adds a component to the game object and registers an undo operation for this action.

If the undo is performed, the newly added component will be destroyed.

public static T AddComponent(GameObject gameObject);

gameObject

The game object you want to add the component to.

T The newly added component.

Generic version.