add Programmyday form github

Warenkorb/Books.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Warenkorb
+{
+    internal class Books : Article
+    {
+        private string author;
+        private string title;
+        private string yearOfPublishing;
+        private double vat = 1.07;
+
+        //Books(int articleNumber, double price,)
+        public Books(int articleNumber, double price, string author, string title, string yearOfPublishing) : base(articleNumber, price)
+        {
+            this.author = author;
+            this.title = title;
+            this.yearOfPublishing = yearOfPublishing;
+        }
+        public override double GetPrice()
+        {
+            return base.GetPrice()*vat; 
+        }
+        public override void PrintInfo()
+        {
+            base.PrintInfo();
+            Console.WriteLine($"Brutto:                 {GetPrice():C2}");
+            Console.WriteLine($"Autor:                  {this.author}");
+            Console.WriteLine($"Titel:                  {this.title}");
+            Console.WriteLine($"Erscheinungsjahr:       {this.yearOfPublishing}");
+        }
+    }
+}