迅速如何检查来自Json的NULL值 [英] swift how can I check for NULL values coming from Json

问题描述

我有一个rest api，并且正在通过Json获取所有数据，然后将其放入IOS TableView中.我的问题是，某些数据在Json

I have a rest api and am getting all data via Json then putting it in a IOS TableView. My issue is that some data is being returned as NULL in Json

"vote_status":null

我试图快速获取该NULL值并将其更改为字符串"0"，但是这样做很难.到目前为止，我有这个

I am trying to get that NULL value in swift and change it to a string "0" but am having a hard time doing so . I have this so far

  if var vote_status = Stream["vote_status"] as? String {
                                if (vote_status == (vote_status)[NSNull]) {
                                   vote_status = "0"
                                }
}

但是我收到此编译错误:

However I get this compile error:

无法用索引类型下标字符串"类型的值 '(NSNull).Type'(aka'NSNull.Type')

Cannot subscript a value of type 'String' with an index of type '(NSNull).Type' (aka 'NSNull.Type')

我这样做是因为 nil 和 null 似乎不起作用，所以我不能这样做.

I am doing this because nil and null does not seem to work so I can't do this.

if (vote_status == nil) ...

推荐答案

您只需要有条件地将字典值强制转换为String，并在出现故障null的情况下使用Nil合并运算符??分配"0":

You just need to conditionally cast your dictionary value to String and use the Nil Coalescing Operator ?? to assign "0" in case of failure null:

let vote_status = Stream["vote_status"] as? String ?? "0"

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