Golang - panic capture / recover

This post will cover a small sample about how to capture or recover from panic in Golang.

Lets check this scenario:

var secondVar interface{}
secondVar = 10
//....
//some code
secondString = secondVar.(string)

What happens in this case?

  panic: interface conversion: interface is int, not string

And when this happens, your program crashes and shuts down. And this can be really bad depending on the situation.

Golang has a recover command / function that allows you to capture this behaviour using a defer:

defer func() {
		if r := recover(); r != nil {
			fmt.Println("Recovered in f", r)
		}
	}()

And now this is printed:

Recovered in f interface conversion: interface is int, not string

This is a nice tool to have when handling APIs to print nicer messages and avoid system crashes.