如何检查任何类型的变量是否为数组 [英] How to check if an variable of any type is an array

问题描述

我尝试将快速协议数组转换为任何数组，但是失败。

I tried to cast a swift protocol array as any array, but failed.

protocol SomeProtocol: class{
}

class SomeClass: NSObject, SomeProtocol{
}

let protocolArray: [SomeProtocol] = [SomeClass()]
let value: Any? = protocolArray

if let _ = value as? [SomeProtocol]{
     print("type check successed")      //could enter this line
}

以上代码可以按预期工作。
但是，我的问题是，我有很多协议，我不想一一检查。添加新协议是不友好的。

Above code could work as expected. However, my problem is, I have a lot of protocols, and I don't want to check them one by one. It is not friendly to add new protocol.

是否有任何方便的方法来检查值上方是否是下面的数组？

Is there any convenience way to do check if above "value" is a kind of array like below?

if let _ = value as? [Any]{
    print("type check successed")    //never enter here
}

编辑：

受Rohit Parsana的回答启发，以下代码可以工作：

Inspired by Rohit Parsana's answer, below code could work:

if let arrayType = value?.dynamicType{
    let typeStr = "\(arrayType)"
    if typeStr.contains("Array"){
         print(typeStr)
    }
}

但是这些代码似乎不够安全，例如，您可以声明一个名为 abcArray的类。

But these code seems not safe enough, for example, you can declare a class named "abcArray".

尽管我们可以使用正则表达式来检查 typeStr是否与 Array< *>，似乎太棘手了。

Although we could use regular expression to check if "typeStr" matches "Array<*>", it seems too tricky.

有没有更好的解决方案？

Is there any better solution?

推荐答案

您可以使用反射：

if value != nil {
    let mirror = Mirror(reflecting: value!)
    let isArray = (mirror.displayStyle == .Collection)
    if isArray {
        print("type check succeeded")
    }
}

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