Use Go reflection to get func type information

Here is a small code snipped that demonstrates how to get type information from a func type in Go. I prints the information to the console. More information about reflection can be found at the great Go docs article The Laws of Reflection.


package main

import (

type Multiplier func(x int, y int) int

func main() {
  m := Multiplier(Multipli)
  mType := reflect.TypeOf(m)

  fmt.Printf("name: %v\n", mType.Name())
  fmt.Printf("number of in args: %v\n", mType.NumIn())
  fmt.Printf("number of out args: %v\n", mType.NumOut())
  fmt.Printf("in arg 1 type: %v\n", mType.In(0).Name())
  fmt.Printf("in arg 2 type: %v\n", mType.In(1).Name())
  fmt.Printf("out arg 1 type: %v\n", mType.Out(0).Name())

func Multipli(x int, y int) int {
  return x * y


$ go run method.go
name: Multiplier
number of in args: 2
number of out args: 1
in arg 1 type: int
in arg 2 type: int
out arg 1 type: int