Hi Ravi To me Aggregation and Composition have same meaning. So, you need only one of them. Car has wheels. ie. Wheels are one part of a car hence Car object will have a reference to Wheel object (may be array of four)... Now, aggregation could be applied as Car does have more than just wheels. It has glasses, windsheild, machine, body etc...So Car is an aggregation of all of those... Regards Maulin
What have you considered, Ravi? You might want to try a quick search for this topic on this forum, the intermediate forum, and the OO forum. It's been discussed quite a few times before, and you might be able to gather some good information from those previous conversations.