英文:
Accessing global var from child package
问题
我正在写一个小的Go应用程序，其中在main.go中定义了一些全局常量，如下所示：
main.go
package main
import (
"github.com/JackBracken/global/sub"
)
const AppName string = "全局字符串"
func main() {
sub.Run()
}
sub/sub.go
package sub
import "fmt"
func Run() {
fmt.Println(AppName)
}
我对Go还不太熟悉，我期望像这样的代码能够工作，但是go build会抛出错误sub/sub.go:6: undefined: AppName。
我知道我可以创建一个globals包，在sub.go中导入它，并使用globals.AppName等来引用我的全局变量，但我想知道是否可能按照我的原始方式来做，或者我是否完全误解了作用域和包的概念？
英文:
I am writing a small go application that has some global consts defined in main.go like below:
main.go
package main
import (
"github.com/JackBracken/global/sub"
)
const AppName string = "global string"
func main() {
sub.Run()
}
sub/sub.go
package sub
import "fmt"
func Run() {
fmt.Println(AppName)
}
I'm pretty new to Go and would expect something like this to work, but go build throws the error sub/sub.go:6: undefined: AppName.
I know I can do something like creating a globals package, import it in sub.go and refer to my global variables with globals.AppName etc., but I'd like to know if it's possible my original way, or am I just completely misunderstanding scoping and packages?
答案1
得分: 10
你不能在其他地方访问'main'包中的符号，这是因为Go语言不允许导入循环。
如果你需要在'main'包和其他包中访问同一个变量，你需要将变量移到另一个包中，这样两个包都可以访问它。所以你的'globals'包是正确的做法。
英文:
You cannot access symbols in the 'main' package anywhere else, for the simple reason that Go does not allow import loops.
If you need to access a variable in both 'main' and some other package, you'll need to move your variables elsewhere, to a package that both can access. So your 'globals' package is the right idea.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论