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Empty Interface Type in Go Programming Language

The type interface{} is known as the empty interface, and it is used to accept values of any type. The empty interface doesn't have any methods that are required to satisfy it, and so every type satisfies it.

Example

package main

import "fmt"

func printType(i interface{}) {
	fmt.Println(i)
}

func main() {
	var manyType interface{}
	manyType = 100
	fmt.Println(manyType)

	manyType = 200.50
	fmt.Println(manyType)

	manyType = "Germany"
	fmt.Println(manyType)

	printType("Go programming language")
	var countries = []string{"india", "japan", "canada", "australia", "russia"}
	printType(countries)

	var employee = map[string]int{"Mark": 10, "Sandy": 20}
	printType(employee)

	country := [3]string{"Japan", "Australia", "Germany"}
	printType(country)
}

The manyType variable is declared to be of the type interface{} and it is able to be assigned values of different types. The printType() function takes a parameter of the type interface{}, hence this function can take the values of any valid type.

Output

100
200.5
Germany
Go programming language
[india japan canada australia russia]
map[Mark:10 Sandy:20]
[Japan Australia Germany]
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