diff --git a/StringService.cs b/StringService.cs
new file mode 100644
index 0000000..331d936
--- /dev/null
+++ b/StringService.cs
@@ -0,0 +1,68 @@
+using System;
+
+namespace StringProcessingApp.Services
+{
+    public class StringService
+    {
+        private string currentText = "";
+        private string originalText = "";
+
+        public void SetText(string text)
+        {
+            currentText = text;
+            originalText = text;
+        }
+
+        public string GetText()
+        {
+            return currentText;
+        }
+
+        public void ToUpperCase()
+        {
+            currentText = currentText.ToUpper();
+        }
+
+        public void ToLowerCase()
+        {
+            currentText = currentText.ToLower();
+        }
+
+        public int CountCharacters()
+        {
+            return currentText.Length;
+        }
+
+        public bool ContainsWord(string word)
+        {
+            return currentText.Contains(word);
+        }
+
+        public void ReplaceWord(string oldWord, string newWord)
+        {
+            currentText = currentText.Replace(oldWord, newWord);
+        }
+
+        public void ExtractSubstring(int startIndex, int length)
+        {
+            if (startIndex >= 0 && startIndex + length <= currentText.Length)
+            {
+                currentText = currentText.Substring(startIndex, length);
+            }
+            else
+            {
+                Console.WriteLine("Invalid substring range.");
+            }
+        }
+
+        public void TrimSpaces()
+        {
+            currentText = currentText.Trim();
+        }
+
+        public void ResetText()
+        {
+            currentText = originalText;
+        }
+    }
+}
diff --git a/Stringview.cs[MERCADO] b/Stringview.cs[MERCADO]
new file mode 100644
index 0000000..8fa1692
--- /dev/null
+++ b/Stringview.cs[MERCADO]
@@ -0,0 +1,113 @@
+using System;
+using StringProcessingApp.Services;
+
+namespace StringProcessingApp.Views
+{
+    public class StringView
+    {
+        private StringService service = new StringService();
+
+        public void Run()
+        {
+            bool running = true;
+
+            while (running)
+            {
+                ShowMenu();
+                Console.Write("Choose an option: ");
+                string choice = Console.ReadLine();
+
+                Console.WriteLine();
+
+                switch (choice)
+                {
+                    case "1":
+                        Console.Write("Enter text: ");
+                        string text = Console.ReadLine();
+                        service.SetText(text);
+                        break;
+
+                    case "2":
+                        Console.WriteLine("Current Text: " + service.GetText());
+                        break;
+
+                    case "3":
+                        service.ToUpperCase();
+                        Console.WriteLine("Converted to UPPERCASE.");
+                        break;
+
+                    case "4":
+                        service.ToLowerCase();
+                        Console.WriteLine("Converted to lowercase.");
+                        break;
+
+                    case "5":
+                        Console.WriteLine("Character Count: " + service.CountCharacters());
+                        break;
+
+                    case "6":
+                        Console.Write("Enter word to check: ");
+                        string word = Console.ReadLine();
+                        Console.WriteLine(service.ContainsWord(word)
+                            ? "Word found!"
+                            : "Word not found.");
+                        break;
+
+                    case "7":
+                        Console.Write("Enter word to replace: ");
+                        string oldWord = Console.ReadLine();
+                        Console.Write("Enter new word: ");
+                        string newWord = Console.ReadLine();
+                        service.ReplaceWord(oldWord, newWord);
+                        Console.WriteLine("Word replaced.");
+                        break;
+
+                    case "8":
+                        Console.Write("Start index: ");
+                        int start = int.Parse(Console.ReadLine());
+                        Console.Write("Length: ");
+                        int length = int.Parse(Console.ReadLine());
+                        service.ExtractSubstring(start, length);
+                        break;
+
+                    case "9":
+                        service.TrimSpaces();
+                        Console.WriteLine("Spaces trimmed.");
+                        break;
+
+                    case "10":
+                        service.ResetText();
+                        Console.WriteLine("Text reset to original.");
+                        break;
+
+                    case "11":
+                        running = false;
+                        Console.WriteLine("Exiting program...");
+                        break;
+
+                    default:
+                        Console.WriteLine("Invalid choice.");
+                        break;
+                }
+
+                Console.WriteLine();
+            }
+        }
+
+        private void ShowMenu()
+        {
+            Console.WriteLine("==== String Processing System ====");
+            Console.WriteLine("1. Enter Text");
+            Console.WriteLine("2. View Current Text");
+            Console.WriteLine("3. Convert to UPPERCASE");
+            Console.WriteLine("4. Convert to lowercase");
+            Console.WriteLine("5. Count Characters");
+            Console.WriteLine("6. Check if Contains Word");
+            Console.WriteLine("7. Replace Word");
+            Console.WriteLine("8. Extract Substring");
+            Console.WriteLine("9. Trim Spaces");
+            Console.WriteLine("10. Reset Text");
+            Console.WriteLine("11. Exit");
+        }
+    }
+}