Java Overview (4) Hello word!

Create a demo.txt

Class demo

{

Public static void main (string [] ARGs ){

System. Out. Print ("Hello word ");

}

}

 

Change the TXT suffix to Java → demo. Java

 

In the D: \ Java directory

 

D: Convert to disk D

CD Java enters the Java File

Javac runs Java program prefix

Javac java. Java

Run the demo class in Java demo to get hello

 

Set the use of temporary environment variables in Doc

1. Why set temporary environment variables? Because the system can find the environment to run Java files at any time

2. Temporary environment variables are temporary and will not be used to repair others' computers.

Set classpath = D: Java

Java demo directly outputs hello

The Java system will automatically find the environment variable, so you can directly use set classpath = D: Java file path.