当json包含没有键的数组时，如何检查在swiftyJSON中是否存在键

I know about swiftyJSON method exists() but it does not seem to work always as they say. How can I get proper result in this case below? I cannot change JSON structure because I am getting this through client's API.

我知道swift json方法的存在()，但它似乎并不总是像人们说的那样工作。在下面这个例子中，我如何得到正确的结果?我不能改变JSON结构，因为我是通过客户端API实现的。

var json: JSON =  ["response": ["value1","value2"]]
if json["response"]["someKey"].exists(){
    print("response someKey exists")
}

Output:

输出:

response someKey exists

That shouldn't be printed because someKey does not exist. But sometimes that key comes from client's API, and i need to find out if it exists or not properly.

不应该打印，因为有些键不存在。但是有时候这个密钥来自客户端的API，我需要知道它是否存在。

1 个解决方案

#1

It doesn't work in your case because the content of json["response"] is not a dictionary, it's an array. SwiftyJSON can't check for a valid dictionary key in an array.

它在您的例子中不起作用，因为json["response"]的内容不是字典，而是数组。SwiftyJSON不能检查数组中的有效字典键。

With a dictionary, it works, the condition is not executed, as expected:

有了字典，它就工作了，条件没有执行，如预期的那样:

var json: JSON =  ["response": ["key1":"value1", "key2":"value2"]]
if json["response"]["someKey"].exists() {
    print("response someKey exists")
}

The solution to your issue is to check if the content is indeed a dictionary before using .exists():

解决您的问题的方法是在使用.exist()之前检查内容是否确实是字典:

if let _ = json["response"].dictionary {
    if json["response"]["someKey"].exists() {
        print("response someKey exists")
    }
}

#1