For Java's understanding, write Hello Word

The history of Java

Java was developed by Sun and launched in May 1995. Oracle (Oracle) acquired Sun for $7.4 billion on April 20, 2009. Access to Java Copyright
The father of Java-James Goslin, born in Canada, is a computer programming genius. When he studied computer science at Carnegie Mellon University, he wrote a multiprocessor version of the UNIX operating system and was the founder of the Java programming language.
Linux is derived from UNIX and presumably you also know. UNIX is a generic term for a class of systems,
Windows-based  MS-DOS (1980, Seattle Computer Products Company (Seattle computer product)
A 24-year-old programmer, Tim Patterson Tim Paterson, spent four months writing the 86-dos operating system.
In July 1981, Microsoft acquired the full copyright of the product to Seattle Corporation at a cost of $50,000 and renamed it MS-DOS. ）

advantages of the Java language 　

Ava operating mechanism and principle
Cross-platform (cross-operating) Windows Linux
JVM Java Virtual machine
. Java->.class (bytecode file)-machine code (binary 0 1) operation mechanism

configuration of environment variables

1, download Java JDK 1.6 1.7 1.8 Currently 1.8 is enough for novice 1.6.

Its predecessor was MS-DOS

2, the installation path can not appear in Chinese, otherwise it may cause some JDK operation can not be done.

3, environment variables, right button properties, my Computer, click Environment---advanced environment, depending on the operating system, the way to add may be different, add the environment to go to the bin directory:

4, Novice can use the text editor to get started, txt or editplus or notepad++ can be. After the build, you must change the suffix name to. java.

5, compiled into a cmd window, enter the Javac compiled file. Java (Note that the program path to be entered correctly, such as the D drive under the D-Disk to compile D: through this command, and then the Java compiled files can be run)

6. Verify that the JDK is installed successfully---Enter Java or Java version or Javac directly under the cmd window

First program Hello work

public class hellowork{

System.out.println ("Hellow Word");

}

The public delegate modifier is used to specify the scope of some programs

A keyword for class creation

Hellowork class name, class name needs attention, first letter capitalization (specification, lowercase does not error.) ）

You cannot start with a number, the symbol can begin with $, the rest cannot be used, you cannot start with the key child of the property method, such as int string, which affects methods in calling this party class.

For Java's understanding, write Hello Word