Objects, classes and more

New Terminology - Actually much of this is review

class

A class is a blueprint or prototype from which objects are created. A set of objects.

object

An instance of a class.  It contains a copy of all of the instance variables defined in the class declaration.

member

Attributes or methods that belong to the class or object. They are directly contained within the class block.

attributes (fields)

Global variables that are the characteristics of the class.

methods

Behaviors or actions of the class.

state

The specific values of an object. (Its attribute values.)

visibility

Applied to class members, visibility defines the scope of the member (public or private).

encapsulation

The combining of attributes and behaviors into a single package that protect that class of objects and their data.

instantiation

The act of creating a new object from a class.

qualified name

A member name that is "qualified" by an object name or a class name.

accessor methods

Methods which access data within an object but do not change the object's state.

mutator methods

Methods which access data within an object and change the state of one or more attributes.

constructor

Special method with the same name as the name of the class that can be used primarily to initialize class fields.

overloaded methods

Two methods with the same name but with different numbers and types of parameters

aliases

Two reference variables that reference the same object.  

call by value

The method of parameter passage in which the value of the actual parameter (argument) is copied into the formal parameter (recipient) in the method.  All method calls in Java are call by value.  In the case of reference types, that call by value is copying the reference from one variable to another.

static

A modifier on either a field or method member of a class which defines that member to belong to the class as a whole instead of to instances of the class.  That means that for fields, there is a single field and value regardless of the number of objects created.

shadowing

The practice of having a field member in a class with the same name as a local variable in a method of the class.  The local variable takes precedence when referred to in the method in which it is defined.  To relieve ambiguity, the keyword this is used to refer to the instance field as in this.variable.

Java Specific Terms

private

The class member is visible only to its own class methods.

public

The class member is visible to any class's methods that chooses to use it.

this

A java reserved word which refers to the calling object.