Golang打印地图内部由json.NewDecoder生成的地图(Golang print map inside map generated by json.NewDecoder)

 我正在使用这里的答案从api中获取一些json： 
 
package main

import (
   "encoding/json"
   "fmt"
   "log"
   "net/http"
)

func main() {
   resp, err := http.Get("http://api.openweathermap.org/data/2.5/forecast?id=524901&appid=1234")
   if err != nil {
      log.Fatal(err)
   }
   var generic map[string]interface{}
   err = json.NewDecoder(resp.Body).Decode(&generic)
   if err != nil {
      log.Fatal(err)
   }
   fmt.Println(generic)
}
 
 它正在工作，我有一个存储在generic变量中的json映射。 
 
 当我打印时： 
 
fmt.Println(generic["city"])
 
 我回来了： 
 
map[id:524901 name:Moscow coord:map[lon:37.615555 lat:55.75222] country:RU population:0 sys:map[population:0]]
 
 现在我想访问城市名称。 我正在尝试以下方法： 
 
fmt.Println(generic["city"]["name"])
 
 我得到错误： 
 
 
 
 muxTest / router.go:30：无效操作：generic [“city”] [“name”]（类型interface {}不支持索引） 
 
 
 还尝试了generic["city"].name不起作用。 
 
 如何访问城市名称值？ 

I'm using the answer here to fetch some json from an api:
 
package main

import (
   "encoding/json"
   "fmt"
   "log"
   "net/http"
)

func main() {
   resp, err := http.Get("http://api.openweathermap.org/data/2.5/forecast?id=524901&appid=1234")
   if err != nil {
      log.Fatal(err)
   }
   var generic map[string]interface{}
   err = json.NewDecoder(resp.Body).Decode(&generic)
   if err != nil {
      log.Fatal(err)
   }
   fmt.Println(generic)
}
 
It's working, I have a map of the json stored in the generic variable.
 
When I print with:
 
fmt.Println(generic["city"])
 
I get back:
 
map[id:524901 name:Moscow coord:map[lon:37.615555 lat:55.75222] country:RU population:0 sys:map[population:0]]
 
Now I want to access the city name. I'm trying the following:
 
fmt.Println(generic["city"]["name"])
 
And I get error:
 
 
 
muxTest/router.go:30: invalid operation: generic["city"]["name"] (type interface {} does not support indexing)
 
 
Also tried generic["city"].name which didn't work.
 
How can I access the city name value?

原文：https://stackoverflow.com/questions/41885456