Go by Example: Panic

A `panic` typically means something went unexpectedly wrong. Mostly we use it to fail fast on errors that shouldn’t occur during normal operation, or that we aren’t prepared to handle gracefully.
	`package main`
	`import "os"`
	`func main() {`
We’ll use panic throughout this site to check for unexpected errors. This is the only program on the site designed to panic.	`panic("a problem")`
A common use of panic is to abort if a function returns an error value that we don’t know how to (or want to) handle. Here’s an example of `panic`king if we get an unexpected error when creating a new file.	`_, err := os.Create("/tmp/file") if err != nil { panic(err) } }`

Running this program will cause it to panic, print an error message and goroutine traces, and exit with a non-zero status.
When first panic in `main` fires, the program exits without reaching the rest of the code. If you’d like to see the program try to create a temp file, comment the first panic out.	`$ go run panic.go panic: a problem`
	`goroutine 1 [running]: main.main() /.../panic.go:12 +0x47 ... exit status 2`
Note that unlike some languages which use exceptions for handling of many errors, in Go it is idiomatic to use error-indicating return values wherever possible.

Next example: Defer.