Whats a good way to fix a zipper that came apart?

You have to start at the very bottom of the zipper and feed the disconnected side of the zipper into the 'slider', making sure that both halves of the zipper will mesh in synchronicity with each other (which means the correct teeth on one side have to be aligned with the correct teeth on the other side), then move the 'slider' up as required.

To stop this from ever happening again, try putting a very tiny safety pin at the very bottom of the zipper track permanently which will prevent the slider from descending too far where and subsequently becomes unhooked from the zipper track.

Counselling

😬 idk can it be? my blasted dog ate the zipper off my coat 😐

Glue the thing to the thingy

Oh my god! I won the prize!!!! 😲

There are many youtubes to help.

There’s a trick with a fork you can see on the youtube.

Sometimes it'll fit back together from the back but it'll probably be jacked up. I bet the internet knows