feat: Add DownCasting class demonstrating upcasting and explicit downcasting

Add a program that:
- Defines a parent class `AnimalFamily` and a subclass `Cat`
- Shows upcasting by referencing a `Cat` object with a parent class type
- Demonstrates explicit downcasting to access subclass-specific methods
- Calls methods from both superclass and subclass to illustrate inheritance behavior.

Author: Someshdiwan

Section5OperatorExpression/src/Downcasting.java

@@ -1,33 +1,18 @@
-/*
-Downcasting: means the typecasting of a parent object to a child object.cannot be implicit.
-
-https://www.scaler.com/topics/upcasting-and-downcasting-in-java/
-
-Explicit Down-casting:
-
-When a subclass type refers to an object of the parent class, the process is referred to as down-casting.
-If it is done manually, the compiler issues a runtime ClassCastException error.
-It can only be done by using the instanceof operator.Only the downcast of an object that has already been upcast is possible.
-*/
-
 import java.io.*;
 class AnimalFamily {
-    public void eat()
-    {
+    public void eat() {
         System.out.println("The animal is eating.");
     }
 }
 
 class Cat extends AnimalFamily {
-    public void meow()
-    {
+    public void meow() {
         System.out.println("The cat is meowing.");
     }
 }
 
 class DownCasting {
-    public static void main(String[] args)
-    {
+    public static void main(String[] args) {
         AnimalFamily animal = new Cat(); // Upcasting: Cat object is referenced by AnimalFamily
         animal = new Cat(); // New Cat object, previous one is lost (Garbage Collected)
         animal = new Cat(); // Another new Cat object
@@ -37,4 +22,17 @@ public static void main(String[] args)
         Cat cat = (Cat)animal;
         cat.meow();
     }
-}
+}
+
+/*
+Down-casting: means the typecasting of a parent object to a child object.cannot be implicit.
+
+https://www.scaler.com/topics/upcasting-and-downcasting-in-java/
+
+Explicit Down-casting:
+
+When a subclass type refers to an object of the parent class, the process is referred to as down-casting.
+If it is done manually, the compiler issues a runtime ClassCastException error.
+It can only be done by using the instanceof operator.
+Only the downcast of an object that has already been upcast is possible.
+*/