ArrayList with Objects which implements an Interface

Question

I want a ArrayList, where you can add Objects , which implements an Interface. Something like this:

ArrayList<Object implements Interface> list =
   new ArrayList<Object which implements a specific Interface>();

What is the correct syntax for this?

How about inheriting from ArrayList and implementing the interface? — Haensl, Jul 02 '15 at 17:34
I dont want the ArrayList to implement the Interface, i want to have the Objects IN the ArrayList implement the Interface. — , Jul 02 '15 at 19:13
You may want to add a [tag](http://stackoverflow.com/help/tagging) to indicate the language you're using. — Bernhard Barker, Jul 04 '15 at 12:36

score 0 · Accepted Answer · answered Jul 04 '15 at 12:33

Just set the interface as the type of the generic. Here you go the code in C#:

interface IFoo {
    void foo();
}

class Foo1 : IFoo {
    public void foo() {
        Console.WriteLine("foo1");
    }
}

class Foo2 : IFoo {
    public void foo() {
        Console.WriteLine("foo2");
    }
}

class Program {
    public static void Main() {
        // IFoo type: any object implementing IFoo may go in
        List<IFoo> list = new List<IFoo>();
        list.Add(new Foo1());
        list.Add(new Foo2());
        foreach(IFoo obj in list) obj.foo(); // foo1, foo2
        Console.ReadKey();
    }
}

ArrayList with Objects which implements an Interface

1 Answers1