Static local variable in Go

Question

Is it possible to define a local variable in Go that can maintain its value from one function call to another? In C, we can do this using the reserved word static.<

Answer 1

You can do something like this

package main

import (
    "fmt"
)

func main() {
  f := do()
  f() // 1
  f() // 2
}

func do() (f func()){
  var i int
  f = func(){
    i++
    fmt.Println(i)
  }
  return
}

Link on Playground https://play.golang.org/p/D9mv9_qKmN

Answer 2

Declare a var at global scope:

var i = 1

func a() {
  println(i)
  i++
}

Answer 3

Use a closure:

Function literals are closures: they may refer to variables defined in a surrounding function. Those variables are then shared between the surrounding function and the function literal, and they survive as long as they are accessible.

It doesn't have to be in global scope, just outside the function definition.

func main() {

    x := 1

    y := func() {
        fmt.Println("x:", x)
        x++
    }

    for i := 0; i < 10; i++ {
        y()
    }
}

(Sample on the Go Playground)