From e2aa8c7cba667df2e43a99e3e3d68316721fcb91 Mon Sep 17 00:00:00 2001
From: Jason Zhu <jasonzhuyq@outlook.com>
Date: Thu, 15 Jul 2021 16:56:14 +1000
Subject: [PATCH] e.g. 5.26 Querying Without LINQ

---
 .../essential_csharp_features/Program.cs      | 37 ++++++++++---------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/chap5_essential_language_features/essential_csharp_features/Program.cs b/chap5_essential_language_features/essential_csharp_features/Program.cs
index ac6522a..aa82ade 100644
--- a/chap5_essential_language_features/essential_csharp_features/Program.cs
+++ b/chap5_essential_language_features/essential_csharp_features/Program.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
 using automatically_implemented_properties;
 
 namespace automatically_implemented_properties
@@ -9,29 +10,31 @@ namespace automatically_implemented_properties
     {
         static void Main(string[] args)
         {
-            // create and populate Shopping Cart, implementing IEnumerable<Product> interface
-            IEnumerable<Product> products = new ShoppingCart
+            Product[] products =
             {
-                Products = new List<Product>
-                {
-                    new Product {Name = "Kayak", Category = "Watersports", Price = 275M},
-                    new Product {Name = "Lifejacket", Category = "Watersports", Price = 48.95M},
-                    new Product {Name = "Soccer ball", Category = "Soccer", Price = 19.50M},
-                    new Product {Name = "Corner flag", Category = "Soccer", Price = 34.95M}
-                }
+                new Product {Name = "Kayak", Category = "Watersports", Price = 275M},
+                new Product {Name = "Lifejacket", Category = "Watersports", Price = 48.95M},
+                new Product {Name = "Soccer ball", Category = "Soccer", Price = 19.50M},
+                new Product {Name = "Corner flag", Category = "Soccer", Price = 34.95M}
             };
 
-            IEnumerable<Product> filteredProducts = products.Filter(prod => 
-                prod.Category == "Soccer" || 
-                prod.Price > 20);
-            
-            foreach (Product prod in filteredProducts) 
+            // define the array to hold results
+            Product[] results = new Product[3];
+            // sort the contents of the array
+            Array.Sort(products, (item1, item2) =>
             {
-                Console.WriteLine("Name: {0}, Price {1:c}", prod.Name, prod.Price);
+                return Comparer<decimal>.Default.Compare(item1.Price, item2.Price);
+            });
+            // get the first three items in the array as the results
+            Array.Copy(products, results, 3);
+            // print out the name
+            foreach (Product p in results)
+            {
+                Console.WriteLine("Item: {0}, Cost: {1}", p.Name, p.Price);
             }
 
-            decimal total = products.FilterByCategory("Soccer").TotalPrices();
-            Console.WriteLine("Filtered total: {0:c}", total);
+            int count = 0;
+            // print the name
         }
 
     }