Question

我是Swift的新手，并且很难在复杂字典中添加新值。下面的代码更新了字典中已存在的值（例如，Jerry和Beth），但如果我尝试添加新值，则字典仅显示两个值而不是三个值。

var locals: [String: Dictionary<String, String>] = ["Jerry":["City":Destination.Seattle.rawValue,"Preference": TravellingPreference.Adventurer.rawValue, "Gender": Gender.Male.rawValue],"Beth":["City":Destination.Seattle.rawValue,"Preference":TravellingPreference.Foodie.rawValue, "Gender": Gender.Female.rawValue]]

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
{
    let citySelected = localInput[0][pickerView.selectedRowInComponent(0)]
    let preferenceSelected = localInput[1][pickerView.selectedRowInComponent(1)]
    var localInformation = LocalsInformation().locals
   if let name = nameTextField.text{
        localInformation[name]?["City"] = citySelected
        localInformation[name]?["Preference"] = preferenceSelected
        localInformation[name]?["Gender"] = "Female"
    print(localInformation)
    }

}

Answer 1

localInformation[name]?["City"] = citySelected

?基本上意味着（在此上下文中）如果localInformation[name]为nil则不会执行任何操作，这很可能就是这种情况。你可能想这样做：

localInformation[name] = [
    "City": citySelected,
    "Preference": preferenceSelected,
    "Gender": "Female"
]

话虽如此，我建议您尽可能使用struct而不是字典。它会更容易处理（因为你不能拼错一把钥匙而你不必处理很多选项），它会让你的代码更加清晰。

将值添加到复杂字典Swift

1 个答案: