empty output after json unmarshal in go, while no parsing error occured [duplicate]

Question

simple go-lang program for parsing json string into self-defined structure.

package main import ( "encoding/json" "fmt" ) type IpInfo struct { ip string `json:"ip"` } type MyData struct { msg string `json:"msg"` status_code int `json:"status_code"` data []IpInfo `json:"data"` } func main() { json_data := []byte(`{"msg": "success", "status_code": 0, "data": [{"ip": "127.0.0.1"}]}`) my_data := MyData{} err := json.Unmarshal(json_data, &my_data) if err != nil { fmt.Println("error:", err) } fmt.Println(my_data.msg) }

I got nothing after ran this code, however "success" was expected.

baduker · Accepted Answer · 2020-09-27 11:44:51Z

You have to export the fields from you struct.

package main import ( "encoding/json" "fmt" ) type IpInfo struct { Ip string `json:"ip"` } type MyData struct { Msg string `json:"msg"` StatusCode int `json:"status_code"` Data []struct{ IpInfo } `json:"data"` } func main() { jsonData := []byte(`{"msg": "success", "status_code": 0, "data": [{"ip": "127.0.0.1"}]}`) myData := MyData{} err := json.Unmarshal(jsonData, &myData) if err != nil { fmt.Println("error:", err) } fmt.Println(myData.Msg) }

Output: success

Also, I'd recommend reading on Go's naming conventions and formatting here. And don't forget to run go fmt on your file.

Collectives™ on Stack Overflow

empty output after json unmarshal in go, while no parsing error occured [duplicate]

1 Answer 1

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Linked

Related