diff --git a/W6/Animal.java b/W6/Animal.java
new file mode 100644
index 0000000..8bf1a88
--- /dev/null
+++ b/W6/Animal.java
@@ -0,0 +1,5 @@
+// 抽象类：动物
+public abstract class Animal {
+    // 抽象方法：发出叫声，没有方法体
+    public abstract void makeSound();
+}
diff --git a/W6/AnimalTest.java b/W6/AnimalTest.java
new file mode 100644
index 0000000..1fa8380
--- /dev/null
+++ b/W6/AnimalTest.java
@@ -0,0 +1,36 @@
+// 测试类：主方法
+public class AnimalTest {
+    public static void main(String[] args) {
+        // 1. 多态：用父类引用指向子类对象
+        Animal dog = new Dog();
+        Animal cat = new Cat();
+
+        System.out.println("=== 动物叫声测试 ===");
+        // 多态调用：根据实际对象类型执行对应方法
+        dog.makeSound(); // 输出：汪汪汪！
+        cat.makeSound(); // 输出：喵喵喵！
+
+        System.out.println("\n=== 游泳功能测试 ===");
+        // 2. 类型判断：只有Dog能游泳，Cat不能
+        if (dog instanceof Swimmable) {
+            Swimmable swimmableDog = (Swimmable) dog;
+            swimmableDog.swim(); // 输出：狗在水里欢快地游泳~
+        }
+
+        if (cat instanceof Swimmable) {
+            // Cat 不实现 Swimmable，所以这段代码不会执行
+            Swimmable swimmableCat = (Swimmable) cat;
+            swimmableCat.swim();
+        } else {
+            System.out.println("猫不会游泳~");
+        }
+
+        System.out.println("\n=== 数组多态遍历 ===");
+        // 3. 用数组存储多个动物，统一调用
+        Animal[] animals = {new Dog(), new Cat()};
+        for (Animal animal : animals) {
+            animal.makeSound();
+        }
+    }
+}
+
diff --git a/W6/Cat.java b/W6/Cat.java
new file mode 100644
index 0000000..e9910c0
--- /dev/null
+++ b/W6/Cat.java
@@ -0,0 +1,8 @@
+// 猫：仅继承动物类，不实现游泳接口
+public class Cat extends Animal {
+    // 重写抽象方法：发出叫声
+    @Override
+    public void makeSound() {
+        System.out.println("喵喵喵！");
+    }
+}
\ No newline at end of file
diff --git a/W6/Dog.java b/W6/Dog.java
new file mode 100644
index 0000000..3d2e9bb
--- /dev/null
+++ b/W6/Dog.java
@@ -0,0 +1,14 @@
+// 狗：继承动物类，实现游泳接口
+public class Dog extends Animal implements Swimmable {
+    // 重写抽象方法：发出叫声
+    @Override
+    public void makeSound() {
+        System.out.println("汪汪汪！");
+    }
+
+    // 实现接口方法：游泳
+    @Override
+    public void swim() {
+        System.out.println("狗在水里欢快地游泳~");
+    }
+}
\ No newline at end of file
diff --git a/W6/Swimmable.java b/W6/Swimmable.java
new file mode 100644
index 0000000..7c1f4f1
--- /dev/null
+++ b/W6/Swimmable.java
@@ -0,0 +1,5 @@
+// 接口：可游泳的
+public interface Swimmable {
+    // 接口方法：游泳
+    void swim();
+}