AP CSA Java OOP Study Guide Flashcards

Vocabulary flashcards covering core Java concepts, object-oriented programming principles, variable scopes, methods, constructors, inheritance, access modifiers, and reference behavior for AP CSA.

Variable

A named storage location that holds a value.

Primitive type

A basic Java data type such as int, double, boolean, or char.

Reference type

A variable that refers to an object, such as String or Student.

Class

A blueprint that defines data and behavior for objects.

Object

An instance of a class.

Method

A named block of code that performs a task.

Parameter

A variable in a method/constructor definition.

Argument

The actual value supplied when a method/constructor is called.

Return value

The value sent back by a method using return.

Constructor

Special code that runs when an object is created and initializes it.

Inheritance

A child class receives accessible members from a parent class.

Instance variable

A variable belonging to an object, declared inside a class but outside methods.

Local variable

A variable declared inside a method, constructor, or block that exists only within that scope.

Static variable

A class-level variable shared by the class rather than belonging separately to each object.

Scope

The region of a program where a variable can be accessed.

void

A Java keyword indicating that a method does not return a value.

this

A keyword used when a parameter and an instance variable have the same name to identify the current object's instance variable.

extends

A keyword that indicates a subclass inherits accessible members from a parent class.

super

A keyword used in a subclass to call a parent class constructor or reference parent members.

Encapsulation

Keeping an object's data protected and controlling access through methods, such as using private instance variables with public getters and setters.

Constructor Overloading

When a class has more than one constructor as long as their parameter lists are different.

Method Overloading

When methods in a class have the same name but different parameter lists.

public

An access modifier making code accessible from other classes.

private

An access modifier restricting code access so it is available only inside the class where it is declared.

null

A value indicating that a reference variable is not currently referring to an object.

NullPointerException

A runtime error caused by calling an instance method through a null reference variable.