Named Return Values | 點燈坊

Go’s return values may be named. If so, they are treated as variables defined at the top of the function.

Version

Go 1.18

Normal Function

package main

import "fmt"

func main() {
  a, b := split(19)
  fmt.Println(a, b)
}

func split(x int) (int, int) {
  y := x / 10
  z := x % 10
  return y, z
}

Line 10

func split(x int) (int, int) {
  y := x / 10
  z := x % 10
  return y, z
}

y and z are return values, but we have to define them first and then return them as usual

Named Return Values

package main

import "fmt"

func main() {
  a, b := split(19)
  fmt.Println(a, b)
}

func split(x int) (y, z int) {
  y = x / 10
  z = x % 10
  return
}

Line 10

func split(x int) (y, z int) {
  y = x / 10
  z = x % 10
  return
}

• (y, z int) : return values are defined in the return type list
• return : a return statement without arguments returns the named return values. This is known as a naked return

Conclusion

• Naked return statements should be used only in short functions. They can harm readability in longer functions

Reference

A Tour of Go, Named return values