Java Classes and Objects Flashcards

Questions and Answers

What is a Class in Java?

An optional keyword used to access members and methods

An instance of a class

The operator used to create an instance of a class

A template used for making Java objects (correct)

What does 'this Reference' do?

An optional keyword used to access the members and methods of a class

What is an Object in Java?

An instance of a class

What is the purpose of the 'new' keyword?

The operator used to create an instance of a class Signup and view all the answers

What is Garbage Collection in Java?

A built-in function of the Java VM that frees memory as objects are no longer needed or referenced Signup and view all the answers

What is a Mutator Method?

A method that changes the state of an object (setter method) Signup and view all the answers

What is an Accessor Method?

A method that returns information about an object back to the calling program (getter method) Signup and view all the answers

What is a Method in object-oriented programming?

A procedure or function that is encapsulated as part of a class Signup and view all the answers

What does it mean to Instantiate an object?

To create a class object using the keyword new Signup and view all the answers

What is Initialization in programming?

The process of assigning a default value to a variable Signup and view all the answers

What does null represent?

An object reference that has not been instantiated Signup and view all the answers

What are Finalizers in Java?

An optional method that is called just before an object is removed by the garbage collector Signup and view all the answers

What is Reference in programming?

The name of a variable that is associated with an object Signup and view all the answers

What is a Constructor in Java?

A special method used to create an instance of a class Signup and view all the answers

Study Notes

Classes and Objects

Class: Serves as a blueprint for creating Java objects, defining properties (attributes) and behaviors (methods).
Object: Represents a specific instance of a class that encapsulates data and methods.
Instantiate: Refers to the process of creating a new object from a class using the new keyword.

Memory Management

Garbage Collection: Automated process by the Java Virtual Machine (JVM) that reclaims memory by removing objects that are no longer in use or referenced.

Methods in Java

Method: Defined function belonging to a class that can modify object state or return information. Methods fall into two main categories:
- Mutator Method (Setter): Alters the state or attributes of an object.
- Accessor Method (Getter): Retrieves information or attributes from an object without modifying its state.

Object Lifecycle

Constructor: A unique method automatically called when an object is created, used for setting initial values for object's attributes.
Finalizers: An optional method invoked before an object is garbage collected, allowing for cleanup actions.
null: Represents a reference not pointing to any instantiated object, indicating that the object is absent.

Additional Concepts

this Reference: A keyword that allows access to the current object's members and methods, helping distinguish between instance variables and parameters.
Reference: The variable name used to interact with an object in memory, pointing to its location.

Variable Management

Initialization: The action of assigning a default or starting value to a variable when it is created.

Description

Test your knowledge on key concepts related to classes, objects, and methods in Java. These flashcards cover important terms like 'class', 'this reference', and 'garbage collection'. Perfect for anyone looking to understand object-oriented programming in Java.