Question

I’ve just read this post about Panic/Recover in Go and I’m not clear on how this differs from try/catch in other mainstream languages.

Answer 1

I keep looking at this question trying to think of the best way to answer it. It’s easiest to just point to the idiomatic uses for panic/recover as opposed to try/catch &| exceptions in other languages, or the concepts behind those idioms (which can be basically summed up as “exceptions should only occur in truly exceptional circumstances”)

But as to what the actual difference is between them? I’ll try to summarize as best I can.

One of the main differences compared to try/catch blocks is the way control flows. In a typical try/catch scenario, the code after the catch block will run unless it propagates the error. This is not so with panic/recover. A panic aborts the current function and begins to unwind the stack, running deferred functions (the only place recover does anything) as it encounters them.

Really I’d take that even further: panic/recover is almost nothing like try/catch in the sense that try and catch are (or at least act like) control structures, and panic/recover are not.

This really stems out of the fact that recover is built around the defer mechanism, which (as far as I can tell) is a fairly unique concept in Go.

There are certainly more, which I’ll add if I can actuate my thoughts a bit better.