#767 – A struct Is Implicitly Sealed

Every struct in C#, whether it is user-defined or defined in the .NET Framework, is sealed–meaning that you can’t inherit from it.  A struct is sealed because it is a value type and all value types are sealed.

A struct can implement an interface, so it’s possible to see another type name following a colon, after the name of the struct.

In the example below, we get a compile-time error when we try to define a new struct that inherits from the one defined above.

    public struct PersonName
    {
        public PersonName(string first, string last)
        {
            First = first;
            Last = last;
        }

        public string First;
        public string Last;
    }

    // Error at compile time: Type 'PersonName' in interface list is not an interface
    public struct AngryPersonName : PersonName
    {
        public string AngryNickname;
    }
Advertisements

About Sean
Software developer in the Twin Cities area, passionate about software development and sailing.

One Response to #767 – A struct Is Implicitly Sealed

  1. Pingback: Dew Drop – January 28, 2013 (#1,488) | Alvin Ashcraft's Morning Dew

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s

%d bloggers like this: