public?class?HelloWorld?{??
????static???String?className?=?"JAVA開發(fā)一班";
????HelloWorld?demo=new?HelloWorld();???
??????public?static?void?main(String[]?args)?{?
??????System.out.println(HelloWorld.className);
	}
}

要?HelloWorld demo=new HelloWorld();有什么用？？

public?class?HelloWorld?{??
??static?String?className?=?"JAVA開發(fā)一班";
???public?static?void?main(String[]?args)?{
???System.out.println(HelloWorld.className);	
???}
}