public class myapp {

 public static void main(String[] args) {

         // TODO Auto-generated method stub

     System.out.println("Hello Java！");

     System.out.print("你好，Java！   ");  //会不会相当于换行。执行完之后换行

     System.out.println("Do You Know?");

     System.out.print("这次该换行了吧！！！");

     System.out.println("");

     System.out.println(""); //会不会空一行

     System.out.println("应该会空一行吧！！！");