feat(FunctionalProgramming): add Main2 demonstrating Predicate with manual loop

What
- Added Main2 class in package FunctionalProgramming.
- Defines Predicate<Integer> isEven to check if a number is divisible by 2.
- Creates list [1,2,3,5,6,7].
- Iterates through list with enhanced for-loop.
- Uses isEven.test(i) inside if-statement and prints even numbers.

Why
- Shows how to apply Predicate without streams, in traditional loop style.
- Demonstrates functional-style condition checks replacing explicit modulus in loop.
- Serves as educational example bridging functional interfaces with imperative iteration.

How
- Declared Predicate<Integer> isEven = x -> x % 2 == 0.
- Declared numbers list.
- Iterated using for-each.
- Checked isEven.test(i) to filter even numbers.
- Printed even numbers (2 and 6).

Logic
- Inputs: list [1,2,3,5,6,7].
- Outputs:
  - 2
  - 6
- Flow:
  1. Define predicate for even check.
  2. Loop through list.
  3. If number satisfies predicate, print it.
  4. Only even numbers pass.
- Edge cases:
  - List with no even numbers → prints nothing.
  - Null values in list would throw NullPointerException when tested.
- Complexity / performance: O(n) for list traversal.
- Concurrency / thread-safety: Safe for single-threaded loop; Predicate is stateless.
- Error handling: No explicit exceptions; relies on valid non-null inputs.

Real-life applications
- Using Predicate as reusable logic component for validation/filters.
- Encapsulating business rules in predicates that can be reused in multiple contexts.
- Educational example of integrating functional programming into traditional loops.

Notes
- Extra isEven.test(i); statement inside block is redundant; has no effect.
- Same logic can be expressed more concisely with streams: numbers.stream().filter(isEven).forEach(System.out::println).
- Predicates are composable (and/or/negate), allowing complex conditions beyond simple modulus checks.

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

Author: Someshdiwan

Java 8 Crash Course/Predicate/src/FunctionalProgramming/Main2.java

@@ -0,0 +1,20 @@
+package FunctionalProgramming;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Predicate;
+
+public class Main2 {
+    public static void main(String[] args) {
+        Predicate<Integer> isEven = x -> x % 2 == 0;
+        List<Integer> numbers = Arrays.asList(1,2,3,5,6,7);
+
+        for(Integer i : numbers) {
+            if(isEven.test(i)) {
+                isEven.test(i);{
+                    System.out.println(i);
+                }
+            }
+        }
+    }
+}