Initial commit

vs4win/Chapter06/PacktLibrary/StringExtensions.cs

@@ -0,0 +1,15 @@
+using System.Text.RegularExpressions; // to get Regex
+
+namespace Packt.Shared;
+
+public static class StringExtensions
+{
+  public static bool IsValidEmail(this string input)
+  {
+    // use a simple regular expression to check
+    // that the input string is a valid email
+
+    return Regex.IsMatch(input,
+      @"[a-zA-Z0-9\.-_]+@[a-zA-Z0-9\.-_]+");
+  }
+}