Specifying attributes and behaviors

We now have a grasp of some basic object-oriented terminology. Objects are instances of classes that can be associated with each other. An object instance is a specific object with its own set of data and behaviors; a specific orange on the table in front of us is said to be an instance of the general class of oranges. That's simple enough, but let's dive into the meaning of those two words, data and behaviors.

Data describes objects

Let's start with data. Data represents the individual characteristics of a certain object. A class can define specific sets of characteristics that are shared by all objects from that class. Any specific object can have different data values for the given characteristics. For example, the three oranges on our table (if we haven't eaten any) could each weigh a different amount. The orange class could have a weight attribute to represent that datum. All instances of the orange class have a weight attribute, but each orange has...