diff --git a/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/ClassConstants.java b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/ClassConstants.java
index 7fb87b4f1e..ad7a5b795e 100644
--- a/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/ClassConstants.java
+++ b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/ClassConstants.java
@@ -16,6 +16,5 @@ public class ClassConstants {
     public static final List<String> contributorGroups = Arrays.asList("contributor", "author");
 
     public static final int MAXIMUM_NUMBER_OF_GUESTS = MAXIMUM_NUMBER_OF_USERS * 10;
-    public static boolean DEFAULT_GROUPS_DEFINED = DEFAULT_GROUPS != null;
 
 }
\ No newline at end of file
diff --git a/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/CompileTimeVariables.java b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/CompileTimeVariables.java
index f9c3231145..7db4bf80a5 100644
--- a/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/CompileTimeVariables.java
+++ b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/CompileTimeVariables.java
@@ -4,14 +4,18 @@ import java.io.PrintWriter;
 
 public class CompileTimeVariables {
 
+    public String ERROR_MESSAGE = ClassConstants.DEFAULT_USERNAME + " not allowed here.";
     public final int MAXIMUM_LOGIN_ATTEMPTS = 5;
 
     public static void main(String[] args) {
         PrintWriter printWriter = System.console().writer();
+        printWriter.write(ClassConstants.DEFAULT_USERNAME);
+
         CompileTimeVariables instance = new CompileTimeVariables();
+        printWriter.println(instance.MAXIMUM_LOGIN_ATTEMPTS);
+
         final String username = "baeldung";
         printWriter.println(username);
-        printWriter.println(instance.MAXIMUM_LOGIN_ATTEMPTS);
     }
 
 }
diff --git a/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/RunTimeVariables.java b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/RunTimeVariables.java
index 0c801a77a4..fe6b0949f6 100644
--- a/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/RunTimeVariables.java
+++ b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/RunTimeVariables.java
@@ -5,8 +5,10 @@ public class RunTimeVariables {
 
     public static void main(String[] args) {
         Console console = System.console();
+
         final String input = console.readLine();
         console.writer().write(input);
+
         final double random = Math.random();
         console.writer().write("Number: " + random);
     }
diff --git a/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/SwitchStatement.java b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/SwitchStatement.java
new file mode 100644
index 0000000000..4242dc8d36
--- /dev/null
+++ b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/SwitchStatement.java
@@ -0,0 +1,17 @@
+package com.baeldung.compiletimeconstants;
+
+public class SwitchStatement {
+
+    private static final String VALUE_ONE = "value-one";
+
+    public static void main(String[] args) {
+        final String valueTwo = "value" + "-" + "two";
+        switch (args[0]) {
+            case VALUE_ONE:
+                break;
+            case valueTwo:
+                break;
+        }
+    }
+
+}