What is an empty interface (interface{}) and how does it differ from any?

In Go, interface{} is an empty interface that contains no methods and can hold a value of any type. It is used to represent any value because all types implement the empty interface.

any is a synonym for interface{}, introduced in Go 1.18 to improve readability and convenience, especially in the context of generics. Essentially, any and interface{} are identical and interchangeable.

Example:

var x interface{} = 42
var y any = "hello"

fmt.Printf("%T %v\n", x, x) // int 42
fmt.Printf("%T %v\n", y, y) // string hello

Thus, there is no functional difference between interface{} and any; they are simply different names for the same type.