JAVA作业

1、环境变量的配置
JAVA_HOME＝C:\Program Files\Java\jdk1.6.0
PATH＝%JAVA_HOME%\bin
CLASSPATH＝.;%JAVA_HOME%\lib\dt.jar;%JAVA_HOME%\lib\tools.jar

2、测试程序
rbtest.java
------------
class rbtest
{
public static void main(String args[])
{System.out.println("This is a simple Java program.");}
}
------------
E:\java>javac rbtest.java

E:\java>java rbtest
This is a simple Java program.

3、作业
class rbt0103
{
public static void main(String[] args)
{
double r=2.3;
System.out.println(2*r*r);
System.out.println(3.1415926*r*r);
}
}