typecasting.go

package main

import "log"

func alterValue(val interface{}) {
	INCR := 10

	switch i := val.(type) {
	case nil:
		log.Println("Nil value")
	case int:
		log.Println(i + INCR)
	case float64:
		log.Println(i + float64(INCR))
	default:
		log.Println("Unknown Value")
	}
}

func main() {
	intVal := 10
	floatVal := 10.4

	alterValue(intVal)
	alterValue(floatVal)
}