diff --git a/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorld.java b/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorld.java
new file mode 100644
index 0000000000..bf0e2c96c2
--- /dev/null
+++ b/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorld.java
@@ -0,0 +1,3 @@
+void main() {
+    System.out.println("Hello, World!");
+}
diff --git a/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorldChild.java b/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorldChild.java
new file mode 100644
index 0000000000..827be7c788
--- /dev/null
+++ b/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorldChild.java
@@ -0,0 +1,7 @@
+package com.baeldung.unnamedclasses;
+
+public class HelloWorldChild extends HelloWorldSuper {
+    void main() {
+        System.out.println("Hello, World!");
+    }
+}
diff --git a/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorldSuper.java b/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorldSuper.java
new file mode 100644
index 0000000000..59c88716a4
--- /dev/null
+++ b/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorldSuper.java
@@ -0,0 +1,7 @@
+package com.baeldung.unnamedclasses;
+
+public class HelloWorldSuper {
+    public static void main(String[] args) {
+        System.out.println("Hello from the superclass");
+    }
+}
diff --git a/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorldWithMethod.java b/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorldWithMethod.java
new file mode 100644
index 0000000000..698516544e
--- /dev/null
+++ b/core-java-modules/core-java-21/src/main/java/com/baeldung/unnamedclasses/HelloWorldWithMethod.java
@@ -0,0 +1,6 @@
+private String getMessage() {
+    return "Hello, World!";
+}
+void main() {
+    System.out.println(getMessage());
+}