Go Empty Interface

We know that interfaces are used to store a set of methods without implementation. In Go, we can also create interfaces without any methods, known as empty interfaces. For example,

 interface {}

Here, we have created an empty interface without any methods.

Variable of Empty Interface in Golang

In Go, we can create variables of the empty interface type. For example,

 package main import "fmt" func main() { // variable of empty interface type var a interface {} fmt.Println("Value:", a) }

Output

 Value: <nil>

Here, we have created a variable of type empty interface. When we print the variable, we get nil as output.

Empty Interface to Pass Function Argument of Any Type

Normally in functions, when we pass values to the function parameters, we need to specify the data type of parameters in a function definition.

However, with an empty interface, we can pass parameters of any data type. For example,

 package main import "fmt" // empty interface as function parameter func displayValue(i interface {}) { fmt.Println(i) } func main() { a := "Welcome to Programiz" b := 20 c := false // pass string to the function displayValue(a) // pass integer number to the function displayValue(b) // pass boolean value to the function displayValue(c) }

Output

 Welcome to Programiz 20 false

In the above example, we have used an empty interface i as the parameter to the displayValue() function.

Now the same function works for any type of parameters (string,numeric, boolean).