biplab malakar I wrote it the way I meant it. Even a simple "Hello World!" program is something. You don't need to target a product.
You've learned 2 or 3 new operators/methods/patterns? Great. Build some sandbox playground and try them out. Do experiments with their functionality and behaviour and combine them with your existing knowledge.
There is no need for a useful end result.
Learn. Try. Delete. Repeat.