import (
  "encoding/json"
  "fmt"
)

func main() {
  var s =  map[string]interface{}{}
  var a  = map[string]interface{}{"b":11111}

  s["nihao"] = map[string]interface{}{"nihao":"dddd","bb":a}
  res,_ := json.Marshal(s)
  resString := string(res)
  fmt.Println(resString)

}