String数组洗牌和List集合洗牌

造牌：

Card[] cards = new Card[54];     int j=0;    for(int i=0; i<=12; i++){      cards[j++]=new Card(i,0);      cards[j++]=new Card(i,1);      cards[j++]=new Card(i,2);      cards[j++]=new Card(i,3);    }      cards[j++]=new Card(13,4);      cards[j++]=new Card(14,4);

洗牌：

//一：数组洗牌：Random r = new Random();for(i=cards.length-1; i>=1; i--){int j=r.nextInt(i);Card t =cards[i];        //将最后一张牌与随机的牌交换，交换之前将原先的值赋予临时变量t，以便于赋给随机牌cards[i]=cards[j];   cards[j]=t;}System.out.println(Arrays.toString(cards));*//*二：List集合进行洗牌List list = new ArrayList();for(int j=0; j<cards.length; j++){list.add(cards[j]);}//通过内部函数shuffle()打乱集合的顺序Collections.shuffle(list);String str="";for(int k=0; k<list.size(); k++){ str+=list.get(k)+", ";}System.out.print("["+str.substring(0,str.lastIndexOf(","))+"]"); System.out.println();*///三、List集合-改进：List<Card> list = new ArrayList<Card>();for(int j=0; j<cards.length; j++){list.add(cards[j]);}Collections.shuffle(list);for(int k=0; k<list.size(); k++){cards[k]= list.get(k);}System.out.println(Arrays.toString(cards));