feat(Package): add Main and MyClass demonstrating Runnable with thread execution

What
- Added MyClass implementing Runnable:
  - Overrides run() to print "Hello i" from 1 to 9.
- Added Main class:
  - Creates MyClass instance.
  - Demonstrates threading by constructing Thread with MyClass.
  - Calls childthread.run() to execute run() logic.

Why
- Illustrates how to implement the Runnable interface and pass it to a Thread.
- Serves as an educational example of Java’s multithreading basics.
- Demonstrates the difference between main thread and additional threads (though run() is used instead of start()).

How
- Implemented Runnable in MyClass.
- In run(), loop prints sequential messages to stdout.
- In Main, instantiated MyClass and wrapped it in a Thread.
- Invoked childthread.run() to call run() method.

Logic
- Inputs: none (loop controlled inside run()).
- Outputs: "Hello 1" through "Hello 9" printed to stdout.
- Flow:
  1. Main thread executes main().
  2. MyClass instance created.
  3. Thread constructed with MyClass.
  4. childthread.run() directly calls run(), executing on main thread.
  5. Loop prints 9 messages.
- Edge cases:
  - Using run() executes on current thread, not a new one. To create a true child thread, start() must be called instead.
  - Loop condition i<+10 is equivalent to i<10; still works as expected.
- Complexity / performance: O(n) with n=9 iterations; trivial.
- Concurrency / thread-safety:
  - Currently no real concurrency since run() is invoked directly.
  - If start() were used, run() would execute on a separate thread.
- Error handling:
  - No exceptions expected.

Real-life applications
- Runnable is the standard way to encapsulate logic for execution in a thread.
- Common for background tasks, parallel computation, or offloading work from main thread.
- This example is suitable for teaching thread basics and pitfalls (run vs start).

Notes
- To actually execute in parallel, replace childthread.run() with childthread.start().
- Loop condition could be simplified to i < 10 for clarity.
- Example demonstrates mechanics of Runnable but not true multithreading yet.

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

Author: Someshdiwan

Java 8 Crash Course/Lambda Expression/Thread Using Lambda Expression/src/Package/Main.java

@@ -0,0 +1,12 @@
+package Package;
+
+public class Main {
+    public static void main(String[] args) {
+        MyClass myclass = new MyClass();
+        //Main thread. One thread runs here.
+
+        //Another Thread runs here. Second Thread.
+        Thread childthread = new Thread(myclass);
+        childthread.run();
+    }
+}