从__NSArrayM中提取值

Question

我已经打印了我想要获得的值，就像这样：

a =  Optional(<__NSArrayM 0x1704494b0>(9))

如何提取值9？ 我写了这个但是错了：let a = (parseJSON[index] as AnyObject).object(forKey: "subjects_count")

Answer 1

试试这个： -

guard let a = (parseJSON[index] as AnyObject).object(forKey: "subjects_count"), let value = a.first else {return}
let stringValue = String(value)
print(stringValue)

Answer 2

使用Swift本机类型和密钥/索引订阅

if let dict = parseJSON[index] as? [String:Any],
   let subjectsCount = dict["subjects_count"] as? [Int], !subjectsCount.isEmpty {
   print(subjectsCount[0])
}