dotnet · BillWagner · Jul 12, 2019
diff --git a/Beginners/Methods.md b/Beginners/Methods.md
@@ -18,4 +18,4 @@ Replace the *name* variable with a *names* variable that has a list of names. Th
           Console.WriteLine($"Hello {name.ToUpper()}!");
      }
 ```
-#### Previous - [Strings & Variables &laquo;](./Strings.md) Home - [Home](../README.md) 
+#### Next: [Coding challenge &raquo;](./Challenge.md)  Previous - [Strings & Variables &laquo;](./Strings.md) Home - [Home](../README.md) 
diff --git a/Beginners/challenge.md b/Beginners/challenge.md
@@ -0,0 +1,8 @@
+# Try it yourself
+
+The code block on this page has an empty method for your to fill in. Write code that removes all the vowels from a `string`. One of the methods you can use with string is `Replace`. That method replaces a set of characters in a string with a replacement. If the replacement string is the empty string (Two quotes with no characters between them: ""), that removes the characters.
+
+``` cs --region challenge --source-file .\myapp\Program.cs --project .\myapp\myapp.csproj 
+```
+
+#### Previous - [Methods &laquo;](./Methods.md) Home - [Home](../README.md) 
diff --git a/Beginners/myapp/Program.cs b/Beginners/myapp/Program.cs
@@ -1,4 +1,5 @@
-using System;
+using Microsoft.VisualBasic.CompilerServices;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 namespace myapp
@@ -31,6 +32,9 @@ static void Main(string region = null,
                 case "collections":
                     Collections();
                     break;
+                case "challenge":
+                    TestChallengeCode();
+                    break;
                 case "handcoded":
                     PascalsTriangle.HardCoded();
                     break;
@@ -90,6 +94,46 @@ public static void Collections()
             #endregion
         }
 
+        public static void TestChallengeCode()
+        {
+            (string arg, string result)[] inputs =
+            {
+                ("Hello World!","Hll Wrld!"),
+                ("Here's a simple sentence.", "Hr's  smpl sntnc."),
+                ("You've learned to manipulate strings in C#. Well Done!" ,"Y'v lrnd t mnplt strngs n C#. Wll Dn!")
+            };
+
+            bool allCorrect = true;
+            foreach (var item in inputs)
+            {
+                var r = RemoveVowels(item.arg);
+
+                if (r == item.result)
+                    Console.WriteLine($"Correct! {item.arg} => {r}");
+                else
+                {
+                    Console.WriteLine($"Try again: {item.arg} !=> {r}");
+                    allCorrect = false;
+                }
+                Console.WriteLine();
+            }
+            if (allCorrect)
+                Console.WriteLine("Congratulations! You solved this challenge!");
+            else
+                Console.WriteLine("Not quite right yet. Try again.");
+        }
+
+        #region challenge
+        public static string RemoveVowels(string inputText)
+        {
+            // Fill in this code and create a string
+            // that removes all the vowels from the input string.
+            // Remember that vowels are 'a', 'e', 'i', 'o' and 'u'. 
+            // Remember to remove both upper and lower case.
+            return inputText;
+        }
+        #endregion
+
         public static void PascalsTriangleHardCoded()
         {
             #region handcoded

diff --git a/global.json b/global.json
@@ -0,0 +1,11 @@
+{
+  "sdk": {
+    "version": "3.0.100-preview6-012264"
+  },
+  "tools": {
+    "dotnet": "3.0.100-preview6-012264"
+  },
+  "msbuild-sdks": {
+    "Microsoft.DotNet.Arcade.Sdk": "1.0.0-beta.19257.7"
+  }
+}