Added comments

VehicleInventory/Car.cs

@@ -3,20 +3,28 @@ using System;
 using System.Collections.Generic;
 using System.Text;
 
+// You'll often see that programmers break their code into multiple files
+// So long as the files are all held in the same namespace, they're accessible
+// to the rest of your program with no extra work. 
+
 namespace VehicleInventory
 {
-	public class Car
+    // Declare a class called car
+	class Car
 	{
 
+        // Set properties
 		public string InventoryNumber;
 		public double Year;
 		public string Make;
 		public string Model;
 		public double Mileage;
 		public decimal Price;
 
+        // Declare a method to get vehicle details
 		public string GetDetails()
 		{
+            // String interpolation to describe the vehicle
 			return $"{InventoryNumber} - {Year} {Make} {Model} - {Mileage} miles - {Price.ToString("C")}";
 		}
 	}

VehicleInventory/FileHelper.cs

@@ -6,15 +6,23 @@ using System.Text;
 
 namespace VehicleInventory
 {
+    // This is a static class that is used to load the inventory from a text file
 	static class FileHelper
 	{
-		public static List<string> LoadInventory(string filepath)
+        // This private function loads a text file into a list of strings based on its lines.
+        // It can be marked as private because it will only be called by the GetCars function
+        // which is accessible to other classes
+		private static List<string> LoadInventory(string filepath)
 		{
+            // Skip the first line because it contains column headings
 			List<string> result = File.ReadAllLines(filepath).ToList().Skip(1).ToList();
 			return result;
 		}
 
 
+        // Take the result of the LoadInventory function, split the lines into an array,
+        // then map the array to a Car instance. Add the car instance to a list of things
+        // that will be returned, and once complete return them all to the calling function
 		public static List<Car> GetCars(string filepath)
 		{
 			List<Car> result = new List<Car>();

VehicleInventory/Program.cs

@@ -8,68 +8,107 @@ namespace VehicleInventory
 	{
 		static void Main(string[] args)
 		{
+            // filepath will be unique to your computer. You must tell the program where the
+            // VehicleInventory.csv file can be found on your hard disk.
 			string filepath = @"/Volumes/krb11010/3220/CarInventory-Complete/VehicleInventory.csv";
+
+            // Use our static FileHelper class defined in the FileHelper file to load our inventory
 			List<Car> cars = FileHelper.GetCars(filepath);
 
+            // This is a neat trick to make a command line application never complete. We use a
+            // while loop with a condition that always evaluates to true (or in this case, is the
+            // keyword true. This way, or program operates inside an infinite loop, and only closes
+            // if we meet a condition that tells it to explicitly. 
 			while (true)
 			{
+                // Clear the window
 				Console.Clear();
+
+                // Provide instructions how to use the program
 				Console.WriteLine("Input the number for what you're trying to search by:");
 				Console.WriteLine("1 - Search by manufacturer");
 				Console.WriteLine("2 - Search by year");
 				Console.WriteLine("3 - Search by mileage range");
 				Console.WriteLine("4 - Search by price range");
 				Console.WriteLine("10 - Exit");
+
+                // Get a response from the person for what they wish to do
 				string action = Console.ReadLine();
 
+                // SCOPE! We want to access our search results later, so we declare an empty list for them
+                // now, use our switch statement to fill them in, and process them after the switch is complete
 				List<Car> searchResult = new List<Car>();
+
+                // Based on the value of our action variable (user's response), do one of the following:
 				switch (action)
 				{
-					case "1":
+					case "1": // Search by manufacturer
+
+                        // Ask for which manufacturer they're looking for?
 						Console.WriteLine("What vehicle manufacturer is the customer interested in?");
 						string make = Console.ReadLine();
 
+                        // Use Linq to parse through the cars list, and retrieve only those entries where
+                        // the Make property equals the value we have stored in the make variable.
+                        // Linq uses a lambda expression to determine which entries should be taken. It is
+                        // essentially passing a short function that is evaluated for each item in the cars
+                        // list. "w" can be anything you want, it simply refers to the item in the list that
+                        // is currently being evaluated. 
 						searchResult = cars.Where(w => w.Make == make).ToList();
 						break;
-					case "2":
+					case "2": // Search by year
+                        // Same process as condition 1
 						Console.WriteLine("What year vehicle is the customer interested in?");
 						double year = Convert.ToDouble(Console.ReadLine());
 
 						searchResult = cars.Where(w => w.Year == year).ToList();
 						break;
-					case "3":
+					case "3": // Search by mileage range
 						Console.WriteLine("What is the minimum number of acceptable miles?");
 						double mileMinimum = Convert.ToDouble(Console.ReadLine());
 
 						Console.WriteLine("What is the maximum number of acceptable miles?");
 						double mileMaximum = Convert.ToDouble(Console.ReadLine());
 
+                        // Essentially the same as the first case, but this time we have to verify that the
+                        // results are greater than the minimum AND (&&) below the maximum.
 						searchResult = cars.Where(w => w.Mileage >= mileMinimum && w.Mileage <= mileMaximum).ToList();
 						break;
-					case "4":
+					case "4": // Search by price range
 						Console.WriteLine("What is the minimum price the customer wants to pay?");
 						decimal priceMinimum = Convert.ToDecimal(Console.ReadLine());
 
 						Console.WriteLine("What is the maximum price the customer wants to pay?");
 						decimal priceMaximum = Convert.ToDecimal(Console.ReadLine());
 
+                        // Same idea as case 3
 						searchResult = cars.Where(w => w.Price >= priceMinimum && w.Price <= priceMaximum).ToList();
 						break;
-					case "10":
+					case "10": // The person wants to exit the program
+                        // Environment is a static class that represents the current computing "environment" and
+                        // contains a method that lets you exit the program. When your program exits, it should
+                        // specify an exit code, and 0 means "Program exited intentionally"
 						Environment.Exit(0);
 						break;
 					default:
+                        // This code runs if none of the above cases are met. We can pretty safely assume
+                        // our user input a bad value.
 						Console.WriteLine("Please input a valid response. Hit return to try again...");
 						Console.ReadLine();
-						continue; // Start over, don't display results
+
+						// Start the loop over because we have no results to display and we need to ask what to do again
+						continue; 
 				}
 
+				// Did we find results?
 				if (searchResult.Count > 0)
 				{
+					// We did, lets show them
 					Console.Clear();
 					Console.WriteLine("Search Results");
 					Console.WriteLine();
 
+					// Loop through the results, using the GetDetails method on the Car class to print out details
 					foreach (Car car in searchResult)
 					{
 						Console.WriteLine(car.GetDetails());
@@ -79,9 +118,13 @@ namespace VehicleInventory
 					Console.WriteLine("Press return to search again");
 					Console.ReadLine();
 				}
-
-				// else No results, try again
-
+				else
+				{
+					// No results were found, let the user know and allow them to try again.
+					Console.WriteLine("No results were found, sorry!");
+					Console.WriteLine("Press return to search again");
+					Console.ReadLine();
+				}
 			}
 		}
 	}