feat: add WrapperDemo2 to demonstrate special Float wrapper behaviors in Java

WHAT was added:
- Example program showing how Java’s `Float` wrapper handles:
  - Division by zero (produces Infinity).
  - Square root results (normal number vs NaN cases).
  - Equality checks with `NaN`, `Infinity`, and primitive values.

KEY BEHAVIORS DEMONSTRATED:
1. Division by zero (`12.5f/0`) → results in `Float.POSITIVE_INFINITY`.
2. `.isInfinite()` → detects whether a float value is infinite.
3. Comparison with constants:
   - `b == Float.POSITIVE_INFINITY` → true when dividing positive number by zero.
   - `b == Float.NEGATIVE_INFINITY` → false in this case (since dividend was positive).
4. `.isNaN()` → correctly identifies "Not a Number" (e.g., result of `0.0f/0.0f`).
5. Comparing with `Float.NaN`:
   - `x == Float.NaN` → **always false** (by IEEE 754 standard).
   - `Float.NaN != Float.NaN` → **always true** (NaN is not equal to itself).

REAL-WORLD APPLICATIONS:
- ✅ Scientific or financial applications: detect invalid computations (e.g., divide by zero).
- ✅ Data validation pipelines: filter out NaN and Infinity values before saving or processing.
- ✅ Simulation engines: distinguish between valid finite results and overflow/undefined cases.
- ✅ Error handling: prevent unexpected crashes by explicitly checking `.isNaN()` or `.isInfinite()`.

IMPORTANT NOTES:
- Never use `==` to check for `NaN`; always use `.isNaN()`.
- Infinity (`+∞` or `-∞`) comparisons with constants (`Float.POSITIVE_INFINITY`, `Float.NEGATIVE_INFINITY`) are valid.
- IEEE 754 floating-point standard ensures these special values behave consistently across platforms.

RULE OF THUMB:
- Use `.isNaN()` and `.isInfinite()` for safe checks.
- Don’t rely on `==` for detecting NaN.

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

Author: Someshdiwan

Section20JAVA.lang.Package/src/WrapperDemo2.java

@@ -2,7 +2,6 @@ public class WrapperDemo2 {
     public static void main(String[] args) {
         float a =12.5f;
         Float b =12.5f/0;
-
         Float c =(float)Math.sqrt(9); //Square root of 9 is 3. then it is a number.
 
         System.out.println(b.equals(a));
@@ -20,4 +19,4 @@ public static void main(String[] args) {
 
         System.out.println(Float.NaN!=Float.NaN);
     }
-}
+}