# JavaScript Detection Boolean

Why does it say SnapExtensions is not defined

I have no idea.

This is mine:

Why the empty slot in the PRIMITIVE "err_try" block? It seems like the empty slot wouldn't need to be there.

It gives an error if you don't

Look at the params. First is try script, second is the catch script, third input is if you want to specify which error to catch. (I think(I could be totally wrong))

It shouldn't need the empty slot. If you don't have it, it should just input null.

@348663451y you're right. (mostly, joecooldoo below is more right. You're probably thinking of Python.)

Thats the var that gets set to the error.

Try it your self.

I mean, instead of using if <error = EXAMPLE_ERROR> then do this script else do this script for that error, you can simply catch one specific error.

Bro. Iv'e been on snap longer. I know more. (Not trying to be offensive.)

Trying to see if Test · WarpedWartWars/Snap-testing@a46bcaa (github.com) fixes it...

Yes. This proves my point. In this case, that "error" upvar is set to what ever is being watched by the prim. (I think)(again I'm not totally sure, we should ask the devs)

Thats what I said.

But have you been on Snap 7 more? These prims have been out for the same time...

I have a lot of snap 7 projects

Ok????