respond to feedback; add note about nullable context

Author: gewarren

snippets/csharp/System/NullReferenceException/Overview/Array1.cs

@@ -1,19 +1,19 @@
-// <Snippet8>
-using System;
+using System;
 
 public class Array1Example
 {
     public static void Main()
     {
+        // <Snippet8>
         string[] values = [ "one", null, "two" ];
         for (int ctr = 0; ctr <= values.GetUpperBound(0); ctr++)
             Console.Write("{0}{1}", values[ctr].Trim(),
                           ctr == values.GetUpperBound(0) ? "" : ", ");
         Console.WriteLine();
+
+        // The example displays the following output:
+        //    Unhandled Exception:
+        //       System.NullReferenceException: Object reference not set to an instance of an object.
+        // </Snippet8>
     }
 }
-// The example displays the following output:
-//    Unhandled Exception:
-//       System.NullReferenceException: Object reference not set to an instance of an object.
-//       at Example.Main()
-// </Snippet8>

snippets/csharp/System/NullReferenceException/Overview/Array2.cs

@@ -1,18 +1,19 @@
-// <Snippet9>
-using System;
+using System;
 
 public class Array2Example
 {
     public static void Main()
     {
+        // <Snippet9>
         string[] values = [ "one", null, "two" ];
         for (int ctr = 0; ctr <= values.GetUpperBound(0); ctr++)
             Console.Write("{0}{1}",
                           values[ctr] != null ? values[ctr].Trim() : "",
                           ctr == values.GetUpperBound(0) ? "" : ", ");
         Console.WriteLine();
+
+        // The example displays the following output:
+        //       one, , two
+        // </Snippet9>
     }
 }
-// The example displays the following output:
-//       one, , two
-// </Snippet9>

snippets/csharp/System/NullReferenceException/Overview/Array3.cs

@@ -1,20 +1,21 @@
-// <Snippet10>
-using System;
+using System;
 
 public class Array3Example
 {
     public static void Main()
     {
+        // <Snippet10>
         int[] values = null;
         for (int ctr = 0; ctr <= 9; ctr++)
             values[ctr] = ctr * 2;
 
         foreach (int value in values)
             Console.WriteLine(value);
+
+        // The example displays the following output:
+        //    Unhandled Exception:
+        //       System.NullReferenceException: Object reference not set to an instance of an object.
+        //       at Array3Example.Main()
+        // </Snippet10>
     }
 }
-// The example displays the following output:
-//    Unhandled Exception:
-//       System.NullReferenceException: Object reference not set to an instance of an object.
-//       at Example.Main()
-// </Snippet10>

snippets/csharp/System/NullReferenceException/Overview/Array4.cs

@@ -1,27 +1,28 @@
-// <Snippet11>
-using System;
+using System;
 
 public class Array4Example
 {
     public static void Main()
     {
+        // <Snippet11>
         int[] values = new int[10];
         for (int ctr = 0; ctr <= 9; ctr++)
             values[ctr] = ctr * 2;
 
         foreach (int value in values)
             Console.WriteLine(value);
+
+        // The example displays the following output:
+        //    0
+        //    2
+        //    4
+        //    6
+        //    8
+        //    10
+        //    12
+        //    14
+        //    16
+        //    18
+        // </Snippet11>
     }
 }
-// The example displays the following output:
-//    0
-//    2
-//    4
-//    6
-//    8
-//    10
-//    12
-//    14
-//    16
-//    18
-// </Snippet11>

snippets/csharp/System/NullReferenceException/Overview/Chain1.cs

@@ -63,9 +63,10 @@ public class Page
         public Uri URL;
         public string Title;
     }
+
     // The example displays the following output:
     //    Unhandled Exception:
     //       System.NullReferenceException: Object reference not set to an instance of an object.
-    //       at Example.Main()
+    //       at Chain1Example.Main()
     // </Snippet6>
 }

snippets/csharp/System/NullReferenceException/Overview/Chain2.cs

@@ -1,10 +1,10 @@
-// <Snippet7>
-using System;
+using System;
 
 public class Chain2Example
 {
     public static void Main()
     {
+        // <Snippet7>
         var pages = new Pages();
         Page current = pages.CurrentPage;
         if (current != null)
@@ -16,11 +16,12 @@ public static void Main()
         {
             Console.WriteLine("There is no page information in the cache.");
         }
+
+        // The example displays the following output:
+        //       There is no page information in the cache.
+        // </Snippet7>
     }
 }
-// The example displays the following output:
-//       There is no page information in the cache.
-// </Snippet7>
 
 public class Pages
 {

snippets/csharp/System/NullReferenceException/Overview/Program.cs

@@ -1,4 +1,2 @@
-// Do something
-using System;
-
-Console.WriteLine("Hello World");
+//NullReturnExample.NoCheckExample();
+NullReturnExample.ExampleWithNullCheck();

snippets/csharp/System/NullReferenceException/Overview/Project.csproj

@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
+    <Nullable>disable</Nullable>
     <TargetFramework>net9.0</TargetFramework>
   </PropertyGroup>
 

snippets/csharp/System/NullReferenceException/Overview/example1.cs

@@ -13,8 +13,9 @@ public static void Main(string[] args)
         //names.Add("Major Major Major");
     }
 }
+
 // Compilation displays a warning like the following:
-//    Example1.cs(10) : warning BC42104: Variable //names// is used before it
+//    warning BC42104: Variable //names// is used before it
 //    has been assigned a value. A null reference exception could result
 //    at runtime.
 //
@@ -23,5 +24,5 @@ public static void Main(string[] args)
 // The example displays output like the following output:
 //    Unhandled Exception: System.NullReferenceException: Object reference
 //    not set to an instance of an object.
-//       at Example.Main()
+//       at UseBeforeAssignExample.Main()
 // </Snippet1>

snippets/csharp/System/NullReferenceException/Overview/example2.cs

@@ -1,5 +1,4 @@
 // <Snippet3>
-using System;
 using System.Collections.Generic;
 
 public class NRE2Example
@@ -23,9 +22,10 @@ private static List<string> GetData()
         return null;
     }
 }
+
 // The example displays output like the following:
 //    Unhandled Exception: System.NullReferenceException: Object reference
 //    not set to an instance of an object.
-//       at Example.PopulateNames(List`1 names)
-//       at Example.Main()
+//       at NRE2Example.PopulateNames(List`1 names)
+//       at NRE2Example.Main()
 // </Snippet3>