Java Learning Diary NUM1

Learning content : Java language Features, path and CLASSPATH environment variables, Java development process;

I. Overview of the Java overview language

1 Overview of the Java overview language

(1) A high-level programming language introduced by Sun (Stanford University Network, Stanford University web Company) in 1995?   (2) is an Internet-facing programming language.  (3) As Java technology continues to mature in the web, it has become the preferred development language for Web applications. (4) is a simple and easy to learn, completely object-oriented, safe and reliable, platform-independent programming language.

2 features of the Java language

1, network-oriented programming language 2, fully object-oriented 3, platform-independent programming language (cross-platform, portability). Principle: Because both windows,linux and other platforms have virtual machines that correspond to the parsing of Java programs. The difference between path and CLASSPATH environment variable 1,path is the system environment variable, and the application can be executed under any directory after setting path. is for execution with the application.      path settings: Set      set path  through My Computer----> Properties-----Advanced-----> Environment Variables You can view the contents of the PATH environment variable   set path =  empty the contents of the PATH environment variable   SET path = xxxx;%path%  preserves the contents of the original PATH environment variable and adds a new environment variable xxxxx 2,classpath  can execute class files through Java in any directory. class file for Java.     classpath settings: 1, through the "My Computer----> Properties-----Advanced-----> Environment Variables" To set, the advantages once and for all.                            2, set classpath under DOS command line.　Features: Shutdown DOS command line, set failure.   Set classpath  can view the contents of the PATH environment variable   set Classpath =  empty the contents of the PATH environment variable   SET classpath = XXXX;%PATH%&N Bsp Keep the original PATH environment variable content, and add new environment variable xxxxx Three, Java development process 1, write, knock Code, Java source file 2, compile, compile Java file by Javac command, generate class file. 3, run, run the file through the Java command.      

Java Learning Diary NUM1