Puzzle of the day -3

Hi Everyone,

Here is the next puzzle .

There are 4 people wearing a cap each , there are 2 white caps and 2 black caps no one knows who are wearing what..

they stood in a way given below.

1 2 3 (wall) 4

1 wearing - white
2 wearing - white
3 wearing - black
4 wearing - black

1 can see 2 and 3 , 2 can see 3 , 3 and 4 can see none .

So the question is who says that he is wearing that cap and too correctly?

People who already knows this question please edit this if need to ...
people who already knows the answer please await others to answer ..

😎😎