Swift 3：從返回nil訪問嵌套字典嗎？

Question

我在嘗試訪問嵌套的Dictionary遇到問題，該Dictionary似乎返回nil 。

這是我的info輸出的類型Dictionary<String, Any> ：

info = ["list_order": 1, "name": Some Text, "id": 1, "menu_items": {
    1 =     {
        "food_name" = "String";
        "food_picture" = "link";
        "food_price" = "2.00";
    };
    2 =     {
        "food_name" = "String";
        "food_picture" = "link";
        "food_price" = "5.00";
        id = 2;
    };
}]

info["menu_items"]的輸出：

info["menu_items"] = {
    1 =     {
        "food_name" = "String";
        "food_picture" = "link";
        "food_price" = "2.00";
        id = 1;
    };
    2 =     {
        "food_name" = "String";
        "food_picture" = "link";
        "food_price" = "5.00";
        id = 2;
    };
}

但是，以下分配在test產生nil ：

let test = info["menu_items"] as? Dictionary<Int, Any>

有什么不明顯的東西還是我不了解基本原理？

Answer 1

如果您的鍵不是Int類型，則很可能是String類型，請使用[String: Any]嘗試一次。

if let menuItems = info["menu_items"] as? [String: Any] {
     print(menuItems)
}