如何使用Go语言从嵌套包中覆盖变量？

Question

How do I override variables in go from package ?

For example:

file1.go

package A

import "A/B"

var Arg1 = "Hello"

file2.go

package A/B

var Arg1 = "World"  

How can I override arg1 in file1.go if arg1 exist in file2.go?

Answer 1

Are you trying to do something like this, where, for example, a specific location (USA), if present, overrides a general location (World)?

// file A/B.go

package B

var location = "USA"

func Location() string {
    return location
}

// file A.go

package A

import "A/B"

var location = "World"

func Location() string {
    loc := B.Location()
    if len(loc) == 0 {
        loc = location
    }
    return loc
}

// file main.go

package main

import (
    "A"
    "fmt"
)

func main() {
    fmt.Println("Hello,", A.Location())
}

Output:

Hello, USA

If not, please provide a better and specific example of what you are trying to do.