在golang func中引用var是否正确？

Question

If I do this:

func main() {
  foo := 1
  go func() {
    fmt.Println(foo)
  }()
}

is referencing foo inside that func wrong?

Answer 1

It is fine, only in changing context needs some attention(in case of local pointer variables):

package main

import (
    "errors"
    "fmt"
)

func test() {
    defer func() { fmt.Println(1) }()
    defer func() { fmt.Println(2) }()
    defer func() { fmt.Println(3) }()
}

func main() {
    test()
    err := errors.New("error 1")
    defer func() { fmt.Println(err) }()
    err = errors.New("error 2")
}

and also see:
https://www.goinggo.net/2014/06/pitfalls-with-closures-in-go.html