BAEL-7055: How can I capitalize the first letter of each word in a string? (#14927)

Co-authored-by: Mo Helmy <135069400+BenHelmyBen@users.noreply.github.com>

core-java-modules/core-java-string-operations-7/src/main/java/com/baeldung/capitalizefirstcharactereachword/CapitalizeFirstCharacterEachWordUtils.java

@@ -0,0 +1,40 @@
+package com.baeldung.capitalizefirstcharactereachword;
+
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.StringUtils;
+
+class CapitalizeFirstCharacterEachWordUtils {
+
+    static String usingCharacterToUpperCaseMethod(String input) {
+        if (input == null || input.isEmpty()) {
+            return null;
+        }
+
+        return Arrays.stream(input.split("\\s+"))
+          .map(word -> Character.toUpperCase(word.charAt(0)) + word.substring(1))
+          .collect(Collectors.joining(" "));
+    }
+
+    static String usingStringToUpperCaseMethod(String input) {
+        if (input == null || input.isEmpty()) {
+            return null;
+        }
+
+        return Arrays.stream(input.split("\\s+"))
+          .map(word -> word.substring(0, 1).toUpperCase() + word.substring(1))
+          .collect(Collectors.joining(" "));
+    }
+
+    static String usingStringUtilsClass(String input) {
+        if (input == null || input.isEmpty()) {
+            return null;
+        }
+
+        return Arrays.stream(input.split("\\s+"))
+          .map(StringUtils::capitalize)
+          .collect(Collectors.joining(" "));
+    }
+
+}

core-java-modules/core-java-string-operations-7/src/test/java/com/baeldung/capitalizefirstcharactereachword/CapitalizeFirstCharacterEachWordUtilsUnitTest.java

@@ -0,0 +1,38 @@
+package com.baeldung.capitalizefirstcharactereachword;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.apache.commons.text.WordUtils;
+import org.junit.jupiter.api.Test;
+
+class CapitalizeFirstCharacterEachWordUtilsUnitTest {
+
+    @Test
+    void givenString_whenUsingCharacterToUpperCaseMethod_thenCapitalizeFirstCharacter() {
+        String input = "hello baeldung visitors";
+
+        assertEquals("Hello Baeldung Visitors", CapitalizeFirstCharacterEachWordUtils.usingCharacterToUpperCaseMethod(input));
+    }
+
+    @Test
+    void givenString_whenUsingSubstringMethod_thenCapitalizeFirstCharacter() {
+        String input = "Hi, my name is azhrioun";
+
+        assertEquals("Hi, My Name Is Azhrioun", CapitalizeFirstCharacterEachWordUtils.usingStringToUpperCaseMethod(input));
+    }
+
+    @Test
+    void givenString_whenUsingStringUtilsClass_thenCapitalizeFirstCharacter() {
+        String input = "life is short the world is wide";
+
+        assertEquals("Life Is Short The World Is Wide", CapitalizeFirstCharacterEachWordUtils.usingStringUtilsClass(input));
+    }
+
+    @Test
+    void givenString_whenUsingWordUtilsClass_thenCapitalizeFirstCharacter() {
+        String input = "smile sunshine is good for your teeth";
+
+        assertEquals("Smile Sunshine Is Good For Your Teeth", WordUtils.capitalizeFully(input));
+    }
+
+}