检查对象是否是 Swift 中的给定类型 [英] Checking if an object is a given type in Swift

问题描述

我有一个由 AnyObject 组成的数组.我想迭代它，并找到所有是数组实例的元素.

I have an array that is made up of AnyObject. I want to iterate over it, and find all elements that are array instances.

如何在 Swift 中检查对象是否属于给定类型?

How can I check if an object is of a given type in Swift?

推荐答案

如果要检查特定类型，可以执行以下操作:

If you want to check against a specific type you can do the following:

if let stringArray = obj as? [String] {
    // obj is a string array. Do something with stringArray
}
else {
    // obj is not a string array
}

您可以使用作为！"如果 obj 不是 [String]

You can use "as!" and that will throw a runtime error if obj is not of type [String]

let stringArray = obj as! [String]

您也可以一次检查一个元素:

You can also check one element at a time:

let items : [Any] = ["Hello", "World"]
for obj in items {
   if let str = obj as? String {
      // obj is a String. Do something with str
   }
   else {
      // obj is not a String
   }
}

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