OOP: When is it an object?

Question

I\'m trying to understand object orientation. I understand it a little bit of course, but sometimes I\'m not 100% clear. How do you decide what should be turned into an object (

Answer 1

Everything can be made into an object.

IMO, the answer to your question is the question - Is the behaviour of the key-hole necessary for my model of the door to be an accurate representation?

When the answer to the above is in the affirmative, go ahead and incorporate it. When the answer to the same question is in the negative, then I'd choose not to.