Create inheritance&polymorphism.java

pls review it and merge it

Author: Yachika9925

inheritance&polymorphism.java

@@ -0,0 +1,27 @@
+class Animal {
+    void sound() {
+        System.out.println("Animal makes a sound");
+    }
+}
+
+class Dog extends Animal {
+    void sound() {
+        System.out.println("Dog barks");
+    }
+}
+
+class Cat extends Animal {
+    void sound() {
+        System.out.println("Cat meows");
+    }
+}
+
+public class AnimalDemo {
+    public static void main(String[] args) {
+        Animal myDog = new Dog();
+        Animal myCat = new Cat();
+
+        myDog.sound();
+        myCat.sound();
+    }
+}