javac 编译时报错
public class test
{
public void sayhello()
{
system.out.println( "hello ");
}
}
---------
D:\javawork\lesson1> javac test.java
test.java:5: package system does not exist
system.out.println( "hello ");
^
1 error

[解决办法]
system.out.println( "hello ");

改成

System.out.println( "hello ");
[解决办法]
JAVA不同于C,要区分大小写
JAVA里面没有system,只有System