interface2.go

package main

import (
	"fmt"
)

func main() {
	var i interface{}
	i = "Go Engineering 2.0"
	i = 2021
	i = 10.55
	r := i.(float64)
	fmt.Println(r)

	var i2 []interface{}
	i2 = append(i2, "Go v2")
	i2 = append(i2, 2022)
	i2 = append(i2, 23.44)

	i = map[int]string{
		0: "GO",
		1: "C",
	}

	i2 = append(i2, i)

	for _, x := range i2 {
		Generic(x)
	}
}

func Generic(i interface{}) {
	switch v := i.(type) {
	case int:
		fmt.Println("Int * 2=", v*2)
	case float64:
		fmt.Println("Float64/2=", v/2)
	case string:
		h := len(v) / 2
		fmt.Println("text:", v, " - Quantidade/2 -> v[h:] + v[:h]=", v[h:]+v[:h])
	case map[int]string:
		for i, v := range v {
			fmt.Println("key:", i, " valeu:", v)
		}
	default:
		fmt.Println("isn't one of the types")
	}

}