Polymorphic Arrays

A base-class array can hold different derived objects and call virtual methods.

PolymorphicArrays.cs

using System;

class Shape
{
    public virtual string Name()
    {
        return "shape";
    }
}

class Circle : Shape
{
    public override string Name()
    {
        return "circle";
    }
}

class Square : Shape
{
    public override string Name()
    {
        return "square";
    }
}

class Program
{
    static void Main()
    {
        string separator = ;
        Shape[] shapes = { new Circle(), new Square() };
        string summary = "";

        foreach (Shape shape in shapes)
        {
            if (summary.Length > 0)
            {
                summary += separator;
            }

            summary += shape.Name();
        }

        Console.WriteLine($"separator={separator}");
        Console.WriteLine($"summary={summary}");
    }
}

using System;

class Shape
{
    public virtual string Name()
    {
        return "shape";
    }
}

class Circle : Shape
{
    public override string Name()
    {
        return "circle";
    }
}

class Square : Shape
{
    public override string Name()
    {
        return "square";
    }
}

class Program
{
    static void Main()
    {
        string separator = ;
        Shape[] shapes = { new Circle(), new Square() };
        string summary = "";

        foreach (Shape shape in shapes)
        {
            if (summary.Length > 0)
            {
                summary += separator;
            }

            summary += shape.Name();
        }

        Console.WriteLine($"separator={separator}");
        Console.WriteLine($"summary={summary}");
    }
}

using System;

class Shape
{
    public virtual string Name()
    {
        return "shape";
    }
}

class Circle : Shape
{
    public override string Name()
    {
        return "circle";
    }
}

class Square : Shape
{
    public override string Name()
    {
        return "square";
    }
}

class Program
{
    static void Main()
    {
        string separator = ;
        Shape[] shapes = { new Circle(), new Square() };
        string summary = "";

        foreach (Shape shape in shapes)
        {
            if (summary.Length > 0)
            {
                summary += separator;
            }

            summary += shape.Name();
        }

        Console.WriteLine($"separator={separator}");
        Console.WriteLine($"summary={summary}");
    }
}

polymorphism Polymorphism uses the derived method that matches the actual object.