How to make a system that checks if an object exists?

[silk aspen]

So I'm making a baldi's basics fangame with a build mode.
And the player has a custom comp named "Player" where it has a bunch of objects (such as Baldi, Spawn and Selector)
Baldi is.. well, the baldi. And the notebook when answered wrong, the notebook makes baldi's state MAD! but if baldi doesn't exists, the notebook wouldn't change the UI to the normal UI so I need to make a system that checks if baldi exists or not... So can YOU help me?

[sharp galleon]

If (baldi) has then
(Script when he exists)
Or else
(Script when he doesn't)