What is the role and purpose of an empty interface in programming?

An empty interface in Go is an interface that contains no methods, written as interface{}. It can hold a value of any type because all types implement the empty interface by default.

The role of the empty interface is to provide a universal container for values of any type, which is useful for creating generic functions, data structures, or working with dynamic data.

Example usage:

func PrintValue(v interface{}) {
    fmt.Println(v)
}

PrintValue(42)
PrintValue("hello")
PrintValue(struct{ Name string }{"Go"})

Here, the PrintValue function accepts an argument of any type thanks to the empty interface.