C# orientato agli oggetti

Composition over Inheritance

Composition keeps classes focused and avoids rigid inheritance hierarchies.

How it works

Assemble behavior from collaborating objects.

Order delegates price calculation to its line items. Each object owns one clear responsibility.

Runnable C# example

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;

record LineItem(string Name, decimal Price);
class Order
{
    public List<LineItem> Items { get; } = new();
    public decimal Total => Items.Sum(item => item.Price);
}

class Program
{
    static void Main()
    {
        var order = new Order();
        order.Items.Add(new("Book", 30m));
        order.Items.Add(new("Pen", 5m));
        Console.WriteLine(order.Total);
    }
}

Expected output

Practice with the debugger

Set a breakpoint on an important assignment or condition, click Debug, and inspect the local values before stepping to the next line.