javaÖй¹Ô캯ÊýµÄµ÷ÓÃ˳Ðò

µ±Ò»¸ö¸´ÔӵĶÔÏó±»¹¹Ôìʱ,ËüµÄ¹¹Ô캯Êý°´ÏÂÃæµÄ˳Ðò±»µ÷ÓÃ(that the order of constructor calls for a complex object is as follows)
    1.Æä»ùÀà(base-class)µÄ¹¹Ô캯Êý±»µ÷ÓÃ,Õâ¸ö²½ÖèÒԵݹéµÄ·½Ê½Öظ´,ËùÒÔ×îµ×²ã(the root of hierarchy)µÄ¹¹Ô캯ÊýÊ×Ïȱ»Ö´ÐÐ,È»ºóÊÇËüÉÏÒ»²ãÅÉÉúÀà(the next-derived class)...Ö±µ½×²ãµÄÅÉÉúÀà(the most-derived class).
The base-class constructor is called. This step is repeated recursively such that the root of the hierarchy is constructed first, followed by the next-derived class, etc., until the most-derived class is reached.)
    2.Èç¹ûÓаüº¬¹Øϵ(composition),ÄÇôËüµÄ³ÉÔ±¶ÔÏó°´ÕÕÉùÃ÷µÄ˳Ðò±»¹¹Ôì.
Member initializers are called in the order of declaration.
    3.ÅÉÉúÀ๹Ô캯ÊýµÄÄÚÈÝ(body)±»Ö´ÐÐ.
The body of the derived-class constructor is called.
    Ò»¸öʵÀý:
class Cake{
   Cake(){System.out.println("Cake()");}
}
class Meal {
  Meal() { System.out.println("Meal()"); }
}
class Bread {
  Bread() { System.out.println("Bread()"); }
}
class Cheese {
  Cheese() { System.out.println("Cheese()"); }
}
class Lettuce {
  Lettuce() { System.out.println("Lettuce()"); }
}
class Lunch extends Meal {
  Lunch() { System.out.println("Lunch()"); }
}
class PortableLunch extends Lunch {
   //if make derived-class object as the menber of the base-class will lead a infinite
   //loop and program will stop because of the memory consumed
   
   //private Sandwich s=new Sandwich(); 
  private Cake a=new Cake();
  PortableLunch() {&n