title: Parse JS array in JSON string as Golang map
body: <p>An API I query returns a JSON where one of the elements should be an array but is wrapped in quotation marks. It seems therefore the "encoding/json" package doesn´t recognize that element as an array.</p>
  
  <p>When I try to make that element accessible as a map I get the error:</p>
  
  <pre><code>interface conversion: interface is string, not []interface {}
  </code></pre>
  
  <p>Playground: <a href="https://play.golang.org/p/K1H01q-Dqc" rel="nofollow">https://play.golang.org/p/K1H01q-Dqc</a></p>
  
  <pre><code>package main
  
  import (
      "fmt"
      "encoding/json"
  )
  
  func check(e error) {
      if e != nil {
          panic(e)
      }
  }
  
  var incomingJson string = `{
      "status":"success",
      "content":"[{\"id\":\"567670128\"},{\"id\":\"567670129\"}]"
      }`
  
  func main() {
  
      // Decode incoming json
      var encodedJson map[string]interface{}
      err := json.Unmarshal([]byte(incomingJson), &amp;encodedJson)
      check(err)
      fmt.Println(encodedJson)
  
      // Accessing "content" data
      contentOjects := encodedJson["content"].([]interface{})
      contentObject0 := contentOjects[0].(map[string]string)
      fmt.Println(contentObject0)
  } 
  </code></pre>
  
  <p>How should I convert/cast the string in <code>["content"]</code> so I can parse it into <code>map[string]string</code>?</p>