Object-oriented programming concepts

What is a class in object-oriented programming?

A blueprint that defines the data and behavior of objects

Which description best defines an object?

An instance of a class with its own state and behavior

In an object, what does its state usually consist of?

The values held in its fields or attributes

Encapsulation is the practice of doing what?

Combining data with related methods and controlling access to internal details

Why are an object's fields often made private?

To control how the object's state is read or changed

What does abstraction provide in object-oriented design?

A simplified interface that hides unnecessary implementation details

What is inheritance?

Allowing a class to acquire or extend features of another class

Which relationship is most directly represented by inheritance?

An is-a relationship

Polymorphism allows code to do what?

Treat objects of different types through a common interface while obtaining type-appropriate behavior

A subclass supplies its own implementation of an inherited method with the same signature. What is this called?

Method overriding

What commonly happens when an overridden method is called through a parent-type reference?

The implementation associated with the actual object is selected

What is the usual purpose of a constructor?

To initialize a newly created object

In object-oriented programming, what is an interface?

A contract specifying operations that implementing types must provide

Which statement best describes an abstract class?

It is intended as a base class and may leave some behavior for subclasses to implement

What is composition in object-oriented design?

Building a class from objects of other classes as components

Why is composition often described as a has-a relationship?

One object contains or uses another object as a component

What is a key benefit of programming to an interface rather than a concrete class?

Implementations can be replaced with less impact on client code

What is the main goal of information hiding?

To limit dependence on implementation details that may change