Updated Rejex to catter for apostrophes in words like John's

java-strings-3/src/main/java/com/baeldung/string/wordcount/WordCounter.java

@@ -10,7 +10,7 @@ public class WordCounter {
         if (arg == null) {
             return 0;
         }
-        final String[] words = arg.split("[\\pP\\s]+");
+        final String[] words = arg.split("[\\pP\\s&&[^']]+");
         return words.length;
     }
 
@@ -32,7 +32,7 @@ public class WordCounter {
         int characterCounter = 0;
 
         while (characterCounter < stringLength) {
-            if (Character.isLetter(arg.charAt(characterCounter)) && flag == SEPARATOR) {
+            if ((Character.isLetter(arg.charAt(characterCounter)) || isAllowedWordPunct(arg.charAt(characterCounter))) && flag == SEPARATOR) {
                 flag = WORD;
                 count++;
             } else if (!Character.isLetter(arg.charAt(characterCounter))) {
@@ -42,4 +42,8 @@ public class WordCounter {
         }
         return count;
     }
+
+    private static boolean isAllowedWordPunct(char charAt) {
+        return charAt == '\'';
+    }
 }

java-strings-3/src/test/java/com/baeldung/string/wordcount/WordCountUnitTest.java

@@ -3,6 +3,9 @@ package com.baeldung.string.wordcount;
 import static org.junit.Assert.assertEquals;
 
 import org.junit.Test;
+
+import java.util.StringTokenizer;
+
 public class WordCountUnitTest {
     private String string1 = "This is a test sentence with eight words";
     private String string2 = "This#is%a test sentence with eight       words";
@@ -10,11 +13,15 @@ public class WordCountUnitTest {
     @Test
     public void givenStringWith8Words_whenUsingRegexCount_ThenResultEqual8() {
         assertEquals(8, WordCounter.countWordsUsingRegex(string2));
+        assertEquals(9, WordCounter.countWordsUsingRegex("no&one#should%ever-write-like,this;but:well"));
+        assertEquals(7, WordCounter.countWordsUsingRegex("the farmer's wife--she was from Albuquerque"));
     }
 
     @Test
     public void givenStringWith8Words_whenUsingManualMethod_ThenWordCountEqual8() {
         assertEquals(8, WordCounter.countWordsManually(string1));
+        assertEquals(9, WordCounter.countWordsManually("no&one#should%ever-write-like,this but   well"));
+        assertEquals(7, WordCounter.countWordsManually("the farmer's wife--she was from Albuquerque"));
     }
 
     @Test