Object-Oriented Programming Vocabulary

Flashcards from lecture notes on Object-Oriented Programming in Java.

Class

A structure that defines the data and the methods to work on that data and serves as a blueprint for an object.

Object

An executable copy of a class, with its own properties and methods.

Public Access Modifier

Allows the class to be accessed by any other class.

Private Access Modifier

Doesn't allow the class to be accessed by any other class.

Default Access Modifier

Used when no access modifier is specified, also called package-private.

Private Property and Method Access Modifier

Only accessible within the class they are declared in

Protected Property and Method Access Modifier

Accessible by subclasses within any package.

Public Property and Method Access Modifier

Accessible from everywhere in the program.

Default Property and Method Access Modifier

Accessible only within the same package (package-private)

Encapsulation

Objects are the most important units in an OOP system and must maintain their integrity.

Constructors

Special methods that are only called during instantiation to assign values upon creation.

Association

Describes a “using” relationship Objects in this relationship maintain their own life cycle, the destruction of one does not cause the destruction of another

Association – Directed

A one-way association where Only instances of one class use instances of the other class Classes whose instances share a directed association relationship with another object would often have a method that accepts instances of the other class as its parameter

Association – Bidirectional

A two-way association where Instances of both classes can perform the associative action to each other

Association – Reflexive

Exists between separate instances of the same class OR to the same instance of a class itself.

Aggregation

A special, more specific kind of Association Describing a part-whole relationship Where the objects still have their own life cycles

Composition

A special, more specific kind of Aggregation Where, like aggregation, the classes in this relationship exhibit a part-whole relationship (specifically “part-of”) However, one class is dependent on the existence of the other class

Unified Modeling Language

Is used to represent a system / entities Aids in object-oriented design process as a tool for visual representation

Multiplicity

Defines the count of objects that are expected to participate in a relationships

Array

Is fixed in terms of size

ArrayList

Is a dynamic array (no need to specify the size) that extends the List interface

Programming Paradigm

A fundamental style of programming answering the question… “How do I think about and solve a problem?”

Java

Is an object-oriented language , both a compiled and interpreted language

Static Keyword

Associates the assigned entity to the class, not an instance Static variable or method can be used by directly referencing the class

Final Keyword

Variables must have a value Methods cannot be overridden Classes cannot be extended

Overloading

Having multiple methods or constructors with the same name but with different signatures