What are instance variables?

• A. Variables that can be accessed by all instances of a class
• B. Variables that are specific to an instance of a class
• C. Global variables shared across all instances
• D. Constants defined for all instances of a class

Answer: (B)

Instance variables are attributes that are specific to an individual instance of a class in object-oriented programming. Each object created from a class can have different values for these instance variables, which means they hold data unique to that specific instance.

When an instance of a class is created, it can initialize its instance variables typically through a constructor method (often __init__ in Python). Each object maintains its state independent of other objects, allowing for encapsulation of data pertaining to each individual object.

For example, if you have a class named Car, and you create two instances of this class—car1 and car2—you might have instance variables like color and model that can hold different values for each car. This means car1.color could be "red," while car2.color could be "blue." This distinction contrasts with class variables, which would be shared among all instances of that class.