class card implements Comparable<card> {
    private int color; //1-4
    private int point; //1-13
    card(int color, int point) {
        this.color = color;
        this.point = point;
    }

    public int compareTo(card cobj) {
        return color * 10 + point - (cobj.color * 10 + cobj.point);
    }

    public String toString() {
        String str=null;
        switch (color) {
        case 0:
            str = "桃";
            break;
        case 1:
            str = "心";
            break;
        case 2:
            str = "梅";
            break;
        case 3:
            str = "方";
            break;
        }
        switch(point)
        {
        case 0:
           str += " A";
           break;
       case 10:
           str += " J";
           break;
       case 11:
           str += " Q";
           break;
       case 12:
           str += " K";
           break;
           default:
               str+=" "+ (point+1);         
        }
        return str;
    }
}

public class test {
    public static void main(String[] args) {
        ArrayList<card> pk=new ArrayList<card>();
        for (int i = 0; i < 52; i++) {
            pk.add(new card((i/13)%4,i%13));
        }
        System.out.println(pk);
        Collections.shuffle(pk); //洗牌
        System.out.println(pk);
        Collections.sort(pk); //排序
        System.out.println(pk);
    }
}

ken_chie wrote:
3楼写得第一行 为什么可以那样定义一个类
能否给说明一下 小弟初学者不明白 为什么
轻指点
谢谢

class Deck
   COLOR = %w(S H D C)  # Spade Heart Diamond Club
   POINT = %w(A 2 3 4 5 6 7 8 9 10 J Q K)
   attr_accessor :cards
   
   def initialize
     @cards = []
     COLOR.each{|c| 
       POINT.each{|p| 
         @cards << Card.new(COLOR.index(c), POINT.index(p))
       }
     }
     self
   end
   
   def shuffle
     52.times{|i| r = rand(52); @cards[i], @cards[r] = @cards[r], @cards[i]}
   end
   
   def sort
     @cards.sort!{|x, y| x <=> y}
   end
   
   def to_s
     @cards.collect{|c| "#{COLOR[c.color]} #{POINT[c.point]}"}.join("\n")
   end
end

class Card
  attr_accessor :color, :point
  def initialize(color, point)
    @color, @point = color, point
  end
  
  def <=>(obj)
    color == obj.color ? point <=> obj.point : color <=> obj.color
  end
end

deck = Deck.new
deck.shuffle
puts "\n----shuffle-----\n#{deck}"
deck.sort
puts "\n----sort-----\n#{deck}"

dreamsky2 wrote:
public int compareTo(card cobj) {
return color * 10 + point - (cobj.color * 10 + cobj.point);
}

10要改为大于12的数才能正确排序