Golang error handling

Go programs express error state with error values.

The error type is a built-in interface similar to fmt.Stringer:

type error interface {
    Error() string
}

Functions often return an error value, and calling code should handle errors by testing whether the error equals nil.

i, err := strconv.Atoi("42")
if err != nil {
    fmt.Printf("couldn't convert number: %v\n", err)
    return
}
fmt.Println("Converted integer:", i)

A nil error denotes success; a non-nil error denotes failure.