BAEL-3120 alfred.samanga@gmail.com

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

@@ -0,0 +1,49 @@
+package com.baeldung.string.wordcount;
+
+import java.util.StringTokenizer;
+
+public class WordCounter {
+    static final int WORD = 0;
+    static final int SEPARATOR = 1;
+
+    public static int countWordsUsingRegex(String arg) {
+        if (arg == null) {
+            return 0;
+        }
+        final String[] words = arg.split("[\\pP\\s&&[^']]+");
+        return words.length;
+    }
+
+    public static int countWordsUsingTokenizer(String arg) {
+        if (arg == null) {
+            return 0;
+        }
+        final StringTokenizer stringTokenizer = new StringTokenizer(arg);
+        return stringTokenizer.countTokens();
+    }
+
+    public static int countWordsManually(String arg) {
+        if (arg == null) {
+            return 0;
+        }
+        int flag = SEPARATOR;
+        int count = 0;
+        int stringLength = arg.length();
+        int characterCounter = 0;
+
+        while (characterCounter < stringLength) {
+            if (isAllowedInWord(arg.charAt(characterCounter)) && flag == SEPARATOR) {
+                flag = WORD;
+                count++;
+            } else if (!isAllowedInWord(arg.charAt(characterCounter))) {
+                flag = SEPARATOR;
+            }
+            characterCounter++;
+        }
+        return count;
+    }
+
+    private static boolean isAllowedInWord(char charAt) {
+        return charAt == '\'' || Character.isLetter(charAt);
+    }
+}

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

@@ -0,0 +1,35 @@
+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";
+
+    @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
+    public void givenAStringWith8Words_whenUsingTokenizer_ThenWordCountEqual8() {
+        assertEquals(8, WordCounter.countWordsUsingTokenizer(string1));
+        assertEquals(3, new StringTokenizer("three blind mice").countTokens());
+        assertEquals(4, new StringTokenizer("see\thow\tthey\trun").countTokens());
+        assertEquals(7, new StringTokenizer("the farmer's wife--she was from Albuquerque", " -").countTokens());
+        assertEquals(10, new StringTokenizer("did,you,ever,see,such,a,sight,in,your,life", ",").countTokens());
+    }
+}