feat: Add Shadowing class to demonstrate variable shadowing in Java

WHAT the code does:
- Defines a class `Shadowing` with a static class variable `x = 90`.
- In `main()`, declares a local variable `x` that **shadows** the class variable.
- Prints the class-level `x` before shadowing, then prints the local `x` after initialization.
- Includes a `fun()` method that prints the class-level `x` (since local `x` is not in scope there).

WHY this matters:
- Demonstrates the concept of **variable shadowing** in Java:
  - A local variable can hide a class or outer scope variable with the same name.
- Helps understand scope resolution in Java.
- Highlights why naming conventions are important to avoid confusion.

HOW it works:
1. Prints static `x = 90` before local `x` is declared.
2. Declares local `x`, then assigns `40`.
3. Prints local `x = 40`, which hides the class variable within `main()`.
4. Calls `fun()` → prints static `x = 90` because local shadowing does not apply there.

Tips & gotchas:
- Declaring but not initializing a local variable (`int x;`) prevents usage until assigned → attempting `System.out.println(x)` before initialization would cause a compile error.
- Shadowing does not delete the outer variable; it just makes it inaccessible in that scope.
- Avoid variable shadowing in production code for clarity — prefer distinct names.
- Can use `ClassName.variable` or `this.variable` (for instance vars) to access shadowed variables explicitly.

Use-cases:
- Educational demonstration of **scope and shadowing**.
- Helps in debugging when multiple variables with the same name cause unexpected behavior.
- Foundation for understanding **lexical scope** and variable lifetime in Java.

Short key: class-shadowing-static-local.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section10Methods/Methods 2.O/src/Shadowing.java

@@ -1,14 +1,18 @@
 public class Shadowing {
-    static int x = 90; // this will be shadowed at line 8
+    static int x = 90; // this will be shadowed at line 12.
+
     public static void main(String[] args) {
         System.out.println(x); // 90
-        int x; // the class variable at line 4 is shadowed by this
-//        System.out.println(x); // scope will begin when value is initialised
+
+        int x;
+        // the class variable at line 2 is shadowed by this.
+        // System.out.println(x);
+        // scope will begin when value is initialised
+
         x = 40;
         System.out.println(x); // 40
         fun();
     }
-
     static void fun() {
         System.out.println(x);
     }