Accessing values from embedded slice in struct

Question

I am trying to access values from an embedded slice in a struct. How can I do so via indexing, and without calling the private embedded object explicitly (which is not even an option when accessing from outside the package), if that's possible at all?

package main

import (
    "fmt"
)

type A struct {
    aSlice
}

type aSlice []string

func main() {
    a := A{[]string{"hello", "world"}}
    fmt.Println(a.aSlice[0]) // works, but can't be accessed outside package
    fmt.Println(a[0]) // doesn't work, but looking for this something like this
}

Also related: [Go: Embedding a primitive type?](http://stackoverflow.com/questions/38811253/go-embedding-a-primitive-type) — icza, Aug 21 '16 at 09:27

score 2 · Accepted Answer · edited May 23 '17 at 12:32

2

I think I found the answer in this post: golang anonymous field of type map

Only fields and methods may be "promoted" when you embed. For everything else they act as just another field.

In this case the struct would be the equivalent of:

type A struct {
    aSlice aSlice
}

Which makes sense why its values are only accessible via A.aSlice indexing.

edited May 23 '17 at 12:32

Community

1
1

answered Aug 21 '16 at 07:21

cleung2010

197
4
12

score 1 · Answer 2 · answered Aug 24 '16 at 05:13

If you declare the slice as a exported type, then you can access the embedded slice. But you still can't do indexing.

package a
type Slice []string
type A struct {
   Slice
}

package main
import "a"
func main() {
  _a := a.AB{[]string{"hello", "world"}}
  fmt.Println(_a.Slice[0])
}

Accessing values from embedded slice in struct

2 Answers2