Java Study 01

http://zhidao.baidu.com/question/492670771.html?qbl=relate_question_0&word=java%20helloworld%20%C0%E0%CA%C7%B9%AB%B9%B2%B5%C4

一个.java文件中只允许出现一个public class,并且用public修饰的类作为文件的名字,例如A.java中
public class A{
//do something
}
class B{
//do something
}
class C{
//do something
}

http://zhidao.baidu.com/link?url=II_VWggHapxp1R8hfwK1VWfGaFBAWRnVfM6bdutuy_-VG5nOwfDgr3NZR7OG5L7EHbWHAI1UB34bz-HHz2SORNtj-6K6WmY7ZtvaUsQO8Ri

public class Demo
{
public static void main(String[] args)
{
System.out.printf(“Hello World!\r\n”);

    Hello hellotest = new Hello();    hellotest.Firsttest();}

}

class Hello
{
void Firsttest()
{
System.out.println(“Hello World1!”);
}
}