How are data and method organized in an object oriented program?

Answer 1

There are 2 ways: "private or protected" and "public". A programmer has the choice of making the object's data either protected or public. Protected means the data associated with that object can be only accessed by the object's own methods. It can't be globally accessed by simply calling the variable. Public means it can be accessed from any function. E.g: Class Person { Protected: Char name; Char hair-colour; change haircolour change name The above class can have an object of person with his name and hair-colour. As you can see it is protected and no one else can change them except your own functions of change hair-colour and change name. That's how data and methods are organized. It is a security feature, called data encapsulation.

Answer 2

You should try and design classes so that they represent real world entities. Once you have the correct granularilty, any data associated with the entity should be added. If you are using Java, then the data should be represented as private members. The most critical data members should also be added as arguments to the constructor so that when an instance is created the data is supplied by the caller. For example, if you are creating an Employee class, you may add employee ID and name as arguments to the constructor. The rest of the data can be set via a series of set methods (one per property). You should also add ge method for all properties.

Now you can proceed to encapsulate the behavior. Most methods alter the state of the object (for example add a Dependent to an Employee object).