diff --git a/core-java-9/src/main/java/com/baeldung/java9/compactstring/CompactStringDemo.java b/core-java-9/src/main/java/com/baeldung/java9/compactstring/CompactStringDemo.java
new file mode 100644
index 0000000000..6aa4ac3247
--- /dev/null
+++ b/core-java-9/src/main/java/com/baeldung/java9/compactstring/CompactStringDemo.java
@@ -0,0 +1,24 @@
+package com.baeldung.java9.compactstring;
+
+import java.util.List;
+import static java.util.stream.Collectors.toList;
+import java.util.stream.IntStream;
+
+public class CompactStringDemo {
+
+    public static void main(String[] args) {
+        long startTime = System.currentTimeMillis();
+        List strings = IntStream.rangeClosed(1, 10_000_000)
+          .mapToObj(Integer::toString).collect(toList());
+        long totalTime = System.currentTimeMillis() - startTime;
+        System.out.println("Generated " + strings.size() + " strings in " 
+          + totalTime + " ms.");
+
+        startTime = System.currentTimeMillis();
+        String appended = (String) strings.stream().limit(100_000)
+          .reduce("", (left, right) -> left.toString() + right.toString());
+        totalTime = System.currentTimeMillis() - totalTime;
+        System.out.println("Created string of length " + appended.length() 
+          + " in " + totalTime + " ms.");
+    }
+}