Interfaces and Abstractions

Interface Polymorphism

Interface-typed collections can call different implementations through one type.

Interface Polymorphism

InterfacePolymorphism.cs 
using System;

interface IFormatter
{
    string Format(string value);
}

class UpperFormatter : IFormatter
{
    public string Format(string value)
    {
        return value.ToUpper();
    }
}

class BracketFormatter : IFormatter
{
    public string Format(string value)
    {
        return "[" + value + "]";
    }
}

class Program
{
    static void Main()
    {
        string word = ;
        IFormatter[] formatters = { new UpperFormatter(), new BracketFormatter() };
        string summary = "";

        foreach (IFormatter formatter in formatters)
        {
            if (summary.Length > 0)
            {
                summary += ",";
            }

            summary += formatter.Format(word);
        }

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

using System;

interface IFormatter
{
    string Format(string value);
}

class UpperFormatter : IFormatter
{
    public string Format(string value)
    {
        return value.ToUpper();
    }
}

class BracketFormatter : IFormatter
{
    public string Format(string value)
    {
        return "[" + value + "]";
    }
}

class Program
{
    static void Main()
    {
        string word = ;
        IFormatter[] formatters = { new UpperFormatter(), new BracketFormatter() };
        string summary = "";

        foreach (IFormatter formatter in formatters)
        {
            if (summary.Length > 0)
            {
                summary += ",";
            }

            summary += formatter.Format(word);
        }

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

using System;

interface IFormatter
{
    string Format(string value);
}

class UpperFormatter : IFormatter
{
    public string Format(string value)
    {
        return value.ToUpper();
    }
}

class BracketFormatter : IFormatter
{
    public string Format(string value)
    {
        return "[" + value + "]";
    }
}

class Program
{
    static void Main()
    {
        string word = ;
        IFormatter[] formatters = { new UpperFormatter(), new BracketFormatter() };
        string summary = "";

        foreach (IFormatter formatter in formatters)
        {
            if (summary.Length > 0)
            {
                summary += ",";
            }

            summary += formatter.Format(word);
        }

        Console.WriteLine($"word={word}");
        Console.WriteLine($"summary={summary}");
    }
}
interface polymorphism Interface polymorphism dispatches to the actual object's implementation.