diff --git a/core-java-modules/core-java-lang-4/pom.xml b/core-java-modules/core-java-lang-4/pom.xml
index f00a9318f7..4813a45fee 100644
--- a/core-java-modules/core-java-lang-4/pom.xml
+++ b/core-java-modules/core-java-lang-4/pom.xml
@@ -39,5 +39,4 @@
             </resource>
         </resources>
     </build>
-      
-</project>
\ No newline at end of file
+</project>
diff --git a/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/Annotations.java b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/Annotations.java
new file mode 100644
index 0000000000..c46c511ea8
--- /dev/null
+++ b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/Annotations.java
@@ -0,0 +1,11 @@
+package com.baeldung.compiletimeconstants;
+
+public class Annotations {
+
+    private final String deprecatedDate = "20-02-14";
+    private final String deprecatedTime = "22:00";
+
+    //@Deprecated(since = deprecatedDate + " " + deprecatedTime) //TODO: Required JDK 9+
+    public void deprecatedMethod() {}
+
+}
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
new file mode 100644
index 0000000000..6c5995a4ea
--- /dev/null
+++ b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/ClassConstants.java
@@ -0,0 +1,19 @@
+package com.baeldung.compiletimeconstants;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class ClassConstants {
+
+    public static final int MAXIMUM_NUMBER_OF_USERS = 10;
+    public static final String DEFAULT_USERNAME = "unknown";
+
+    public static final Logger log = LoggerFactory.getLogger(ClassConstants.class);
+    public static final List<String> contributorGroups = Arrays.asList("contributor", "author");
+
+    public static final int MAXIMUM_NUMBER_OF_GUESTS = MAXIMUM_NUMBER_OF_USERS * 10;
+
+}
\ 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
new file mode 100644
index 0000000000..c783a1368b
--- /dev/null
+++ b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/CompileTimeVariables.java
@@ -0,0 +1,21 @@
+package com.baeldung.compiletimeconstants;
+
+import java.io.PrintWriter;
+
+public class CompileTimeVariables {
+
+    public final String errorMessage = ClassConstants.DEFAULT_USERNAME + " not allowed here.";
+    public final int maximumLoginAttempts = 5;
+
+    public static void main(String[] args) {
+        PrintWriter printWriter = System.console().writer();
+        printWriter.println(ClassConstants.DEFAULT_USERNAME);
+
+        CompileTimeVariables instance = new CompileTimeVariables();
+        printWriter.println(instance.maximumLoginAttempts);
+
+        final String username = "baeldung" + "-" + "user";
+        printWriter.println(username);
+    }
+
+}
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
new file mode 100644
index 0000000000..53e567fe54
--- /dev/null
+++ b/core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/RuntimeVariables.java
@@ -0,0 +1,16 @@
+package com.baeldung.compiletimeconstants;
+
+import java.io.Console;
+public class RuntimeVariables {
+
+    public static void main(String[] args) {
+        Console console = System.console();
+
+        final String input = console.readLine();
+        console.writer().println(input);
+
+        final double random = Math.random();
+        console.writer().println("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;
+        }
+    }
+
+}