diff --git a/core-java-modules/core-java-string-apis-2/src/main/java/com/baeldung/diffstringstringbuffer/MemoryAddress.java b/core-java-modules/core-java-string-apis-2/src/main/java/com/baeldung/diffstringstringbuffer/MemoryAddress.java
new file mode 100644
index 0000000000..42a4d9d4b4
--- /dev/null
+++ b/core-java-modules/core-java-string-apis-2/src/main/java/com/baeldung/diffstringstringbuffer/MemoryAddress.java
@@ -0,0 +1,33 @@
+package com.baeldung.diffstringstringbuffer;
+
+import java.lang.reflect.Field;
+
+import sun.misc.Unsafe;
+
+public class MemoryAddress {
+    public long getMemoryAddress(Object object) {
+        Object[] arrayOfObject = new Object[]{object};
+        Unsafe unsafe = null;
+        try {
+            Field field = Unsafe.class.getDeclaredField("theUnsafe");
+            field.setAccessible(true);
+            unsafe = (Unsafe) field.get(null);
+        } catch (NoSuchFieldException | IllegalAccessException e) {
+            e.printStackTrace();
+        }
+        assert unsafe != null;
+        long arrayBaseOffset = unsafe.arrayBaseOffset(Object[].class);
+        int addressSize = unsafe.addressSize();
+        long objectAddress;
+        if (addressSize == 4) {
+            objectAddress = unsafe.getInt(arrayOfObject, arrayBaseOffset);
+        } else {
+            if (addressSize == 8) {
+                objectAddress = unsafe.getLong(arrayOfObject, arrayBaseOffset);
+            } else {
+                throw new Error("Error: Size not supported: " + addressSize);
+            }
+        }
+        return objectAddress;
+    }
+}
diff --git a/core-java-modules/core-java-string-apis-2/src/test/java/com/baeldung/diffstringstringbuffer/StringBufferUnitTest.java b/core-java-modules/core-java-string-apis-2/src/test/java/com/baeldung/diffstringstringbuffer/StringBufferUnitTest.java
new file mode 100644
index 0000000000..adbe69b65e
--- /dev/null
+++ b/core-java-modules/core-java-string-apis-2/src/test/java/com/baeldung/diffstringstringbuffer/StringBufferUnitTest.java
@@ -0,0 +1,18 @@
+package com.baeldung.diffstringstringbuffer;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class StringBufferUnitTest {
+    @Test
+    void whenStringBufferVariableIsReassigned_thenVariableRetainsOriginalMemoryAddress() {
+        MemoryAddress memoryAddress = new MemoryAddress();
+        StringBuffer stringBuffer = new StringBuffer("DownTown");
+        long address1 = memoryAddress.getMemoryAddress(stringBuffer);
+        stringBuffer.insert(0, "Coder");
+        assertEquals(stringBuffer.toString(), "CoderDownTown");
+        long address2 = memoryAddress.getMemoryAddress(stringBuffer);
+        assertEquals(address1, address2);
+    }
+}
diff --git a/core-java-modules/core-java-string-apis-2/src/test/java/com/baeldung/diffstringstringbuffer/StringUnitTest.java b/core-java-modules/core-java-string-apis-2/src/test/java/com/baeldung/diffstringstringbuffer/StringUnitTest.java
new file mode 100644
index 0000000000..bf1fcfeaf1
--- /dev/null
+++ b/core-java-modules/core-java-string-apis-2/src/test/java/com/baeldung/diffstringstringbuffer/StringUnitTest.java
@@ -0,0 +1,29 @@
+package com.baeldung.diffstringstringbuffer;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class StringUnitTest {
+    @Test
+    void whenStringVariableIsReassigned_thenVariableGetsNewMemoryAddress() {
+        MemoryAddress memoryAddress = new MemoryAddress();
+        String s1 = "DownTown";
+        long address1 = memoryAddress.getMemoryAddress(s1);
+        s1 = "Coder";
+        long address2 = memoryAddress.getMemoryAddress(s1);
+        assertNotEquals(address1, address2);
+    }
+
+    @Test
+    void whenStringsAreIncludedInAStringBuffer_thenThoseStringsRemainImmutable() {
+        String s1 = "TopCat";
+        StringBuffer stringBuffer = new StringBuffer("DownTown");
+        stringBuffer.append(s1);
+        stringBuffer.reverse();
+        assertNotEquals(s1, "taCpoT");
+        stringBuffer.delete(0, 3);
+        assertEquals(s1, "TopCat");
+    }
+}