Golang：多重结构马歇尔号问题：json格式

Question

For the following code, I get the error:

type A struct{
    B_j []B `json:"A"` 
}
type B struct
{
    X string
    Y string

}

func main() {
    xmlFile, _ := os.Open("test.xml")

    b, _ := ioutil.ReadAll(xmlFile)

    var t root
    err2 := xml.Unmarshal(b, &rpc)
    if err2 != nil {
        fmt.Printf("error: %v", err2)
        return
    }

    for _, name := range t.name{
        t := A{B_j : []B{X : name.text, Y: name.type }} // line:#25

        s, _ := json.MarshalIndent(t,"", " ")

    os.Stdout.Write(s)
        }
}

---

# command-line-arguments
./int2.go:25: undefined: X
./int2.go:25: cannot use name.Text (type string) as type B in array or slice literal
./int2.go:25: undefined: Y
./int2.go:25: cannot use name.type (type string) as type B in array or slice literal

In my output, I am trying to achieve something like this:

{A: {{X:1 ,Y: 2}, {X:2 ,Y: 2}, {X: 2,Y: 2}}}

Struct calling another struct to get the pattern above.

Answer 1

It seems you have problem at this line-

t := A{B_j: []B{X: name.text, Y: name.type }}

You're not creating a slice properly. Try following-

t := A{B_j: []B{{X: name.text, Y: name.type}}}

---

Let's do it better way-

var bj []B
for _, name := range t.name{
  bj = append(bj, B{X: name.text,Y: name.type})
}

t := A{B_j: bj}
s, _ := json.MarshalIndent(t,"", " ")      
os.Stdout.Write(s)

Sample program with static values https://play.golang.org/p/a2ZDV8lgWP

Note: type is language keyword, do not use it as variable name.