Java Basics-Introductory article __java

Access to a language, first from its foundation, only to understand the basics in order to expand in this language. For Java, the same truth.

Attach a picture first

three kinds of technical framework Java 2 Platform Enterprise Edition) Enterprise Edition

is a set of solutions for developing applications in an enterprise environment. The technology system includes technology such as service JSP, mainly for Web application development. The J2SE (Java 2 platform Standard Edition) Standard Edition provides solutions for common desktop and business applications. Is the basis of the other two. You can do some desktop application development. Like the Java version of Minesweeper. J2ME (Java 2 Platform Micro Edition) Small edition is a solution for developing consumer products and embedded devices. The technology system is mainly used in small electronic consumer products. such as applications in mobile phones and so on. Java5.0 version, renamed as: Java EE javase javame language Environment

JRE (Java Runtime Environment Java Runtime Environment) includes Java virtual machines (JVM Java VM virtual Machine) and core class libraries required by Java programs. The JDK (Java Development Kit Java Development Kit) JDK is used by Java developers, including Java development tools and JRE, so that the JDK is installed without having to install the JRE separately. Development tools: Compilation tool (Javac.exe) packaging tool (Jar.exe)

Command line command Human-computer interaction is available in two ways: graphical interface and command line mode

Graphical interface (graphical User Interface GUI): This approach is straightforward, easy to use and easily accessible to users.

Command-Line (command line Interface CLI): You need to have a console, enter a specific instruction, and let the computer do some action. More trouble, need to record some instructions.

When used, we can only remember some common commands,

Dir: Lists the files and folders currently under

MD: Creating a Directory

CDS: Entering specified directory

CD..: Returning to the previous level of directory

cd\: Return root directory

CLS: Clear Screen

CTRL + C: End dead Loop

Exit: Quit DOS

Help: Helping

Of course, there are a lot of command lines, and we just need to remember help, which is easy to handle (pictured below). You can also obtain help for a command, such as a "helping CD", to explain the CD command in detail.

Language Basics:

If you have studied other languages, you will probably know that the basis of each language is roughly the same, and there are only nuances. Keyword identifier annotation constants and variable operator statement functions array

In the learning of these knowledge is, we only know the essence of two points can be:

1. What is the form of manifestation?

2. When to use.

The basis for these languages here and not to detail, for the more important or more classic questions, will be in the post in the back of the present, please look forward to.

Summary:

The basis of each language seems simple, but very important, understanding of the thorough will be to the later learning to play a multiplier effect. Therefore, it is important to lay a good foundation in the early stage, and continue to refuel.