How to parse JSON string to struct - json

Question

I have struct of Request, value is optional:
type Request struct {
Operation string `json:"operation"`
Key string `json:"key"`
Value string `json:"value"`
}
And function that should parse json string to struct^
go func() {
s := string("{'operation': 'get', 'key': 'example'}")
data := Request{}
json.Unmarshal([]byte(s), data)
log.Printf("Operation: %s", data.Operation)
}
For some reason data.Operation is empty. What is wrong here?

Answer 1

Two problems, first, your json is invalid, it needs to use " instead of '
Second, you have to unmarshal into &data and not to data
https://play.golang.org/p/zdMq5_ex8G
package main
import (
"fmt"
"encoding/json"
)
type Request struct {
Operation string `json:"operation"`
Key string `json:"key"`
Value string `json:"value"`
}
func main() {
s := string(`{"operation": "get", "key": "example"}`)
data := Request{}
json.Unmarshal([]byte(s), &data)
fmt.Printf("Operation: %s", data.Operation)
}
Side note, you would have seen this, if you would have been checking your errors:
s := string("{'operation': 'get', 'key': 'example'}")
err := json.Unmarshal([]byte(s), data)
if err != nil {
fmt.Println(err.Error())
//json: Unmarshal(non-pointer main.Request)
}
err := json.Unmarshal([]byte(s), &data)
if err != nil {
fmt.Println(err.Error())
//invalid character '\'' looking for beginning of object key string
}