NSObject和Struct之间的区别

我想知道的区别NSObject和struct..Following例如将解释这两种情况下

在 struct

struct UserDetails{
    var userName:String
    var userID:String
    var userAge:String
    func userDescription()->String{
        return "name " + userName + "age " + userAge
    }
}

在NSObject课堂上

class UserDetails: NSObject {
    var userName:String?
    var userID:String?
    var userAge:String?
    func userDescription()->String{
        return "name " + userName! + "age " + userAge!
    }
}

你能告诉我在哪里必须NSObject上课,我必须在哪里使用struct..？

1)结构通过值传递,类实例通过引用传递2)类可以是子类,结构不能.

Class是否是NSObject的子类(大多数)是无关紧要的.你也可以说:

class UserDetails {
    var userName:String?
    var userID:String?
    var userAge:String?
    func userDescription()->String{
        return "name " + userName! + "age " + userAge!
    }
}