added sort and replace

Metoder/Form1.cs

@@ -1,6 +1,9 @@
 using System;
+using System.Drawing;
 using System.Net.Security;
 using System.Reflection;
+using System.Text;
+using System.Windows.Forms;
 using static System.Net.Mime.MediaTypeNames;
 
 namespace Metoder
@@ -12,10 +15,19 @@ namespace Metoder
             InitializeComponent();
         }
 
+        // button binds
         private void btn_find_Click(object sender, EventArgs e)
         {
-            string searchWord = txtbx_find.Text;
-            Highlight(searchWord);
+            string pattern = txtbx_find.Text;
+            Highlight(pattern);
+        }
+
+        private void btn_replace_Click(object sender, EventArgs e)
+        {
+            string pattern = txtbx_find.Text;
+            string replacement = txtbx_replace.Text;
+
+            ReplaceFound(pattern, replacement);
         }
 
         private void btn_clear_Click(object sender, EventArgs e)
@@ -23,6 +35,13 @@ namespace Metoder
             lbl_found.Visible = false;
         }
 
+        private void btn_sort_Click(object sender, EventArgs e)
+        {
+            SortWords();
+        }
+
+
+        // methods
         void UpdateFindResult(int foundCount)
         {
             lbl_found.Visible = true;
@@ -37,18 +56,26 @@ namespace Metoder
             lbl_found.Text = foundCount.ToString() + suffix;
         }
 
-        (int start, int length) FindTextIndex(string text, int startIndex)
+        Dictionary<int, int> GetMatchesIndices(string pattern, string text)
         {
-            int start = (text.IndexOf(text, startIndex, StringComparison.OrdinalIgnoreCase));
-            if (start == -1) return (-1, 0);
+            Dictionary<int, int> dict = new Dictionary<int, int>();
 
-            return (start, text.Length);
+            if (pattern == "") return dict; // avoid errors, infinite loop
+
+            int index = 0;
+
+            // find and save start index and length of each occurance
+            while ((index = text.IndexOf(pattern, index, StringComparison.OrdinalIgnoreCase)) != -1)
+            {
+                dict[index] = pattern.Length;
+                index += pattern.Length;
+            }
+
+            return dict;
         }
 
-        void Highlight(string word)
+        void Highlight(string pattern)
         {
-            if (word == "") return; // avoid errors, infinite loop
-
             RichTextBox richTextBox = txtbx_text;
             string text = richTextBox.Text;
 
@@ -57,17 +84,13 @@ namespace Metoder
             richTextBox.SelectionBackColor = richTextBox.BackColor;
 
             int found = 0;
-            int caret = richTextBox.SelectionStart; // set cursor
+            int caret = richTextBox.SelectionStart; // set cursor to start
 
-            var words = GetWords();
-            int index = 0;
-
-            while ((index = text.IndexOf(word, index, StringComparison.OrdinalIgnoreCase)) != -1)
+            foreach (KeyValuePair<int, int> occurance in GetMatchesIndices(pattern, text))
             {
-                richTextBox.Select(index, word.Length); // select word
-                richTextBox.SelectionBackColor = Color.LightBlue;
-                found++; // count found
-                index = index + word.Length; // offset (ignore word next loop)
+                richTextBox.Select(occurance.Key, occurance.Value); // select pattern occurance
+                richTextBox.SelectionBackColor = Color.LightBlue; // highlight
+                found++;
             }
 
             // reset cursor
@@ -77,17 +100,70 @@ namespace Metoder
             UpdateFindResult(found);
         }
 
+        void ReplaceFound(string pattern, string replacement)
+        {
+            string text = txtbx_text.Text;
+
+            Dictionary<int, int> matches = GetMatchesIndices(pattern, text);
+
+            if (matches.Count == 0) return;
+
+            string finalString = "";  // or string.Empty
+            int currentIndex = 0;
+
+            foreach (KeyValuePair<int, int> occurrence in matches)
+            {
+                // add text before occurrence
+                if (occurrence.Key > currentIndex)
+                {
+                    finalString += text.Substring(currentIndex, occurrence.Key - currentIndex);
+                }
+
+                // add replacement to result
+                finalString += replacement;
+
+                // move past occurrence
+                currentIndex = occurrence.Key + occurrence.Value;
+            }
+
+            // add remaining text
+            if (currentIndex < text.Length)
+            {
+                finalString += text.Substring(currentIndex);
+            }
+
+            txtbx_text.Text = finalString;
+        }
+
+        void SortWords()
+        {
+            List<string> words = GetSortedWords(GetWords());
+
+            string finalString = "";
+
+            // add each sorted word separated by spaces
+            foreach (string word in words)
+            {
+                finalString += word;
+                finalString += " ";
+            }
+
+            txtbx_text.Text = finalString;
+        }
+
+        List<string> GetSortedWords(List<string> words)
+        {
+            words.Sort();
+
+            return words;
+        }
+
         List<string> GetWords() // get list of words separated by spaces
         {
             string text = txtbx_text.Text;
-            string[] words = text.Split((char[])null, StringSplitOptions.RemoveEmptyEntries);
+            string[] words = text.Split((char[])null, StringSplitOptions.RemoveEmptyEntries); // split by spaces
 
             return words.ToList();
         }
-
-        private void btn_replace_Click(object sender, EventArgs e)
-        {
-
-        }
     }
 }