Which statement about classes and objects is true?

Which statement about classes and objects is true?

• A. They are the same
• B. A class is an instance of an object
• C. An object is an instance of a class
• D. They are unrelated

Answer: (C)

In object-oriented concepts, a class defines a blueprint for objects, specifying what data they hold and what operations they can perform. An object is a concrete, instantiated instance created from that blueprint, with its own specific values. So an object is an instance of a class. For example, imagine a class that models a patient record with fields like patientID, name, and dateOfBirth, plus a method to update diagnoses. A specific patient, such as Jane Doe with a unique patientID, is an object created from that class. The other statements don’t fit: a class is not an instance of an object (that would reverse the relationship), they are not the same (a template vs. a concrete item), and they are not unrelated (they are directly connected through instantiation).

In object-oriented concepts, a class defines a blueprint for objects, specifying what data they hold and what operations they can perform. An object is a concrete, instantiated instance created from that blueprint, with its own specific values. So an object is an instance of a class.

For example, imagine a class that models a patient record with fields like patientID, name, and dateOfBirth, plus a method to update diagnoses. A specific patient, such as Jane Doe with a unique patientID, is an object created from that class.

The other statements don’t fit: a class is not an instance of an object (that would reverse the relationship), they are not the same (a template vs. a concrete item), and they are not unrelated (they are directly connected through instantiation).