title: Decoding JSON int into string
body: <p>I have this simple JSON string where I want <code>user_id</code> to be converted into <strong>string</strong> when doing <code>json.Unmarshal</code>:</p>
  
  <pre><code>{"user_id": 344, "user_name": "shiki"}
  </code></pre>
  
  <p>I have tried this:</p>
  
  <pre><code>type User struct {
    Id       string `json:"user_id,int"`
    Username string `json:"user_name"`
  }
  
  func main() {
    input := `{"user_id": 344, "user_name": "shiki"}`
    user := User{}
    err := json.Unmarshal([]byte(input), &amp;user)
    if err != nil {
      panic(err)
    }
  
    fmt.Println(user)
  }
  </code></pre>
  
  <p>But I just get this error:</p>
  
  <pre><code>panic: json: cannot unmarshal number into Go value of type string
  </code></pre>
  
  <p>Playground link: <a href="http://play.golang.org/p/mAhKYiPDt0">http://play.golang.org/p/mAhKYiPDt0</a></p>