golang:我如何访问json解码字段？

我有下一个JSON数据：

因此，我尝试迭代的内容（如PHP中的foreach）是：发票->发票（是一个数组）

所以，我想做的是：

package main
import (
    "fmt"
    "reflect"
    "encoding/json"
)

func main() {
    json_string := `{"result":"success","totalresults":"494","startnumber":0,"numreturned":2,"invoices":{"invoice":[{"id":"10660","userid":"126","firstname":"Warren","lastname":"Tapiero","companyname":"ONETIME","invoicenum":"MT-453","date":"2014-03-20","duedate":"2014-03-25","datepaid":"2013-07-20 15:51:48","subtotal":"35.00","credit":"0.00","tax":"0.00","tax2":"0.00","total":"35.00","taxrate":"0.00","taxrate2":"0.00","status":"Paid","paymentmethod":"paypalexpress","notes":"","currencycode":"USD","currencyprefix":"$","currencysuffix":" USD"},{"id":"10661","userid":"276","firstname":"koffi","lastname":"messigah","companyname":"Altech France","invoicenum":"","date":"2014-03-21","duedate":"2014-03-21","datepaid":"0000-00-00 00:00:00","subtotal":"440.00","credit":"0.00","tax":"0.00","tax2":"0.00","total":"440.00","taxrate":"0.00","taxrate2":"0.00","status":"Unpaid","paymentmethod":"paypal","notes":"","currencycode":"USD","currencyprefix":"$","currencysuffix":" USD"}]}}`

    var dat map[string]interface{}
    if err := json.Unmarshal([]byte(json_string), &dat); err != nil {
        panic(err)
    }

    invoices := dat["invoices"]

    fmt.Println("\nJSON-VALUE:",json_string)
    fmt.Println("\nVar type:",invoices)
    fmt.Println("\nVar type using REFLECT:",reflect.TypeOf(invoices))

    for index,value := range invoices.invoice {
        fmt.Println(index,value)
    }

}

但是我收到了如下错误：invoices.invoice未定义（类型接口{}没有字段或方法invoice）

所以，拜托，我需要一些帮助，这是我第一天的围棋

---

非常感谢。

当您执行

发票：=dat[“发票”]

时，

发票的类型是
接口{}
，可以是任何东西

实际上，它是一个
map[string]接口{}
。要将
接口{}
转换为它的具体类型，需要使用这样的

for index,value := range invoices.(map[string]interface{}) {
    fmt.Println(index,value)
}

有关完整示例，请参见

但是，如果这个结构定义得很好（并非所有的json都是），那么我会定义一个可以使代码更易于阅读的结构。不要忘记在结构名中使用大写字母，然后用
json:“name”
标记命名（请参阅）