access the common methods from each objects by iterating through a list

Question

I have multiple types of object instances that inherit from a common interface. I would like to access the common methods from each objects by iterating through a list or arraylist or collections. how do I do that?

    {

    interface ICommon
    {
        string getName();
    }

    class Animal : ICommon
    {
        public string getName()
        {
            return myName;
        }
    }

    class Students : ICommon
    {
        public string getName()
        {
            return myName;
        }
    }

    class School : ICommon
    {
        public string getName()
        {
            return myName;
        }
    }


   }

When I add the animal, student, and School in an object[], and try to access in a loop like

for (loop)
{
   object[n].getName // getName is not possible here. 
   //This is what I would like to have.
or 
   a = object[n];
   a.getName // this is also not working. 
}

is it possible to access the common method of different types in from a list or collections?

Answer 1

You need to either cast the object to ICommon

var a = (ICommon)object[n];
a.getName();

Or perferably you should use an array of ICommon

ICommon[] commonArray = new ICommon[5];
...
commonArray[0] = new Animal();
...
commonArray[0].getName();

Or you might want to consider using a List<ICommon>

List<ICommon> commonList = new List<ICommon>();
...
commonList.Add(new Animal());
...
commonList[0].getName();

Answer 2

Just use an "ICommon" array instead of using an "Object" array, otherwise when you retrieve the items of the "Object" array you will have to cast them.