Go 不能超过 <my var>(类型接口 {})

Question

我还处于学习围棋的初级阶段。目前，我正在模拟一个API请求，该请求返回一个json格式的字符串，其中包含一个对象数组。我试图找出最合适的方法来迭代每个记录和访问每个字段。最终，每个字段都将写入Excel电子表格，但现在我只想打印每个字段的键& &;价值。

这是我所拥有的(我将在Go Playground中提供它，但不支持HTTP请求):

    response, err := http.Get("http://go-proto.robwilkerson.org/demo.json")
    failOnError(err, "Uh oh")
    defer response.Body.Close()
    var view []interface{}
    json.NewDecoder(response.Body).Decode(&view)
    log.Printf(" [x] Pulled JSON: %s", view)
    for _, record := range view {
        log.Printf(" [===>] Record: %s", record)
        for key, val := range record {
            log.Printf(" [========>] %s = %s", key, val)
        }
    }

一切正常，直到嵌套循环试图遍历保存每条记录属性的map:

cannot range over record (type interface {})

我想我有两个问题:

1. 嵌套循环是访问每个记录的每个属性的最有效/高效的手段吗?
2. 我需要做些什么来解决这个错误?

当我转储解码到view变量的数据时，这是记录的结果:

[
    map[id:ef14912f-8031-42b3-8c50-7aa612287534 avatar:http://placehold.it/32x32 name:Vilma Hobbs email:[e-mail] phone:[phone] address:471 Dahill Road, Jacksonwald, Alabama, 6026] 
    map[id:1b7bf182-2482-4b8b-8210-9dc9ee51069e avatar:http://placehold.it/32x32 name:Anne Dalton email:[e-mail] phone:[phone] address:660 Macdougal Street, Ticonderoga, Alaska, 7942] 
    map[id:f8027852-f52e-4bbb-bc9d-fb5e34929b40 avatar:http://placehold.it/32x32 name:Amie Ray email:[e-mail] phone:[phone] address:878 Kane Street, Derwood, Minnesota, 3826] 
    map[id:b9842ab7-5053-48b4-a991-f5c63af8fb7e avatar:http://placehold.it/32x32 name:Hope Benton email:[e-mail] phone:[phone] address:396 Osborn Street, Rowe, Massachusetts, 702] 
    map[id:8f9f6d8d-d14e-4ddc-acb2-eb96d3c3d7a8 avatar:http://placehold.it/32x32 name:Janine Kidd email:[e-mail] phone:[phone] address:173 Manhattan Court, Hall, Virginia, 7376] 
    map[avatar:http://placehold.it/32x32 name:Kristen Yang email:[e-mail] phone:[phone] address:203 Doughty Street, Westmoreland, Rhode Island, 849 id:210a6ae6-8227-4f26-a47c-448c400f26e9] 
    map[name:Murray Sosa email:[e-mail] phone:[phone] address:811 Kingsland Avenue, Shepardsville, Hawaii, 9117 id:05f4f6af-19af-4b76-9aa8-9352281cf7d9 avatar:http://placehold.it/32x32] 
    map[phone:[phone] address:176 Underhill Avenue, Ebro, Washington, 8099 id:9d21268d-067c-4b16-a6cd-42d184c4c059 avatar:http://placehold.it/32x32 name:Paige Stanton email:[e-mail]] 
    map[id:9946c19f-c226-4ff3-b578-57a249f8d0c7 avatar:http://placehold.it/32x32 name:Melisa Oconnor email:[e-mail] phone:[phone] address:768 Wallabout Street, Cotopaxi, Florida, 3388] 
    map[id:ee0b82cb-4990-428b-ba36-088287a404ba avatar:http://placehold.it/32x32 name:Monique Poole email:[e-mail] phone:[phone] address:232 Hubbard Place, Islandia, Michigan, 3722]
]

Answer 1

当未声明类型时，json包将解码为的默认值为:

bool, for JSON booleans
float64, for JSON numbers
string, for JSON strings
[]interface{}, for JSON arrays
map[string]interface{}, for JSON objects
nil for JSON null

由于每个record(在您的示例中)是一个json对象，您可以将每个map[string]interface{}断言为如下所示:

for _, record := range view {
    log.Printf(" [===>] Record: %s", record)
    if rec, ok := record.(map[string]interface{}); ok {
        for key, val := range rec {
            log.Printf(" [========>] %s = %s", key, val)
        }
    } else {
        fmt.Printf("record not a map[string]interface{}: %vn", record)
    }
}