Swift: looping into array of dictionaries (Error: Any is not convertible to NSDictionary)

问题

I'm trying to run for loop in an Array of dictionaries. But I'm getting this error:

 Any is not convertible to NSDictionary

Here is my implementation:

let content:NSArray = json .object(forKey: "books") as! NSArray

for contentDic:NSDictionary in content {

        print(contentDic)

    }

How can I cast contentDic to Dictionary or NSDictionary without having this error?

I'll really appreciate your help.

回答1:

If you can guarantee that your content is an array of NSDictionary, you can:

    for contentDic:NSDictionary in content as! [NSDictionary] {
        print(contentDic)

    }

回答2:

Consider the native Swift way:

if let content = json .object(forKey: "books") as? [[String:Any]]
    for contentDic in content {
            print(contentDic)
    }
}

Neither annotate types the compiler can infer nor use NSDictionary / NSArray in Swift. The Foundation collection types defeat the strong type system.

来源：https://stackoverflow.com/questions/43528883/swift-looping-into-array-of-dictionaries-error-any-is-not-convertible-to-nsdi