Knowing the terms before learning Java is useful
for understand the JAVA tutorial easier. The Quick Definition of terms in this
article are from “Eclipse And Java For Total Beginners Companion Tutorial
Document” by Mark Dexter, For details, please reference from the link placing
at end of this article.
1)
Access Modifier
Reserved words “public”, “private”,
“protected” in Java. Control whether classes and members may be accessed from
any class, only this class, subclasses. Default is access from any class in the
package.
2)
Agile (or Extreme) Development
Methodology for developing software that
emphasizes, among other things, unit testing as part of development process.
3)
API (Application Programming
Interface)
The way one program uses another program.
In Java, the API can be thought of as the collection of public methods for a
class or package.
4)
Class
Main building block in Java. Contains
members, including fields and methods. Classes are the “blueprint” for creating
objects.
5)
Constructor
Special block of code used to create an
instance of a class (or, if you
prefer, an object whose type is the class).
Used with the “new” keyword
(e.g., Person p = new Person() calls the
Person() constructor).
6)
Field
Member in a class that holds data (e.g.,
name, age, etc.). Usually marked
private so that other programs cannot
directly access.
7)
IDE (Integrated Development Environment)
Program, like Eclipse, that provides the
different tools required to develop a software package.
8)
JVM (Java Virtual Machine)
(also known as Java Runtime Engine or JRE)
The program that runs Java programs on a
specific platform. Java source code is compiled into .class files. These
contain the instructions used by the JVM to actually run the programs on a
Windows PC, a Linux computer, a Mac computer, etc. The JVM is written for each
platform supported by Java.
9) JUnit
Test
A Java class used to test individual
methods in a class. Used to build test
cases, e.g., when using agile development
methodology.
Method Member in a class that does some
processing (e.g., like a subroutine or
function in other languages).
10) Method
Member in a class that does some processing
(e.g., like a subroutine or function in other languages).
11) Method Argument, Method Parameter
Parameters refers to the list of variables
in a method declaration. Arguments are the actual values that are passed in
when the method is invoked. When you invoke a method, the arguments used must
match the declaration's parameters in type and order. For example, in the
method, public setName(String name) {…}“name” is the parameter for this method.
If this method is used as follows: myObject.setName(“Fred”); “Fred” is the
argument of the method and it must match the type of the method’s parameter
12) Method Signature
A method’s name plus it’s parameter list.
For example, a method defined as “setName (String name)” has a method signature
of “setName(String)”.
Method signatures are important because
they allow methods to be overloaded (i.e., have the same name but different
signatures). For example, the method “setName(String firstName, String
lastName) could be an overload of “setName(String name)” because it as a
different signature (“setName(String, String)”).
13) Object
An instance of a class. For example, Cookie
could be a class, and a cookie (e.g. “thisCookie”) would be an object created
using the class. In other words, “thisCookie” is an object of type Cookie or an
instance of Cookie
14) Overload (Method)
To provide multiple methods with the same
name but different parameters (i.e., same name but different signatures).
15) Override
(Method) When a subclass implements a
method inherited from the super class, this method is said to be overridden.
16) Package
Packages are imported into a source file to
save typing the full name of the class (e.g., can say “Person” instead of org.eclipsetraining.librarytutorial.Person”
and to avoid the possibility of two classes having identical names.
17) Project
In Eclipse, a way to organize your work. An
Eclipse workspace can contain multiple projects. Each project can contain
multiple packages. Each package can contain multiple classes.
18) Refactor
To improve a program without changing the
way it works (i.e., its API). Example include renaming fields or variables,
streamlining code, etc. Very
important in agile development because of
emphasis on self-documenting code.
19) Reference Variable
In Java, variable that holds an object
reference (e.g., p = new Person();). Points to an area on the “heap” where the
object resides. Contrast with
value variable.
20) Scrapbook Page
Area in Eclipse where you can execute Java
code “snippets” and see how they work. Great for experimenting with Java
statements.
21) Static Method
A method that belongs to the entire class
instead of one instance of the class. Invoked with <Class>.<Method>
(e.g., Person.getTotalCount()).
Used for methods that don’t rely on any one
instance of a class.
22) Swing
A set of standard Java packages that
implement a graphical user interface without using any “native” code.
23) SWT (Standard Widget Toolkit)
Set of Java classes and native programs
developed by Eclipse to allow Java programs to have the look and feel of native
programs on each platform. Used to create the Eclipse IDE.
24) Type
In Java, an attribute of a variable to
indicate either a primitive type (int, boolean, etc.) or class membership. For
objects, the type is the class to which it belongs. Types also include
interfaces and enumerations.
25) Value Variable
In Java, variable that holds the value of a
Java primitive (e.g., integer, character, etc.). Held in the memory stack.
Contrast with reference variable.
26) Workspace
Top-level container for Eclipse work. Holds
multiple projects. In a single Eclipse session, only one workspace can be
active.
* * *
Material from:
Eclipse And Java For Total Beginners
Companion Tutorial Document
Copyright © 2007 Mark Dexter. Licensed
under the Educational Community License version 1.0
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