Java基础加强

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面向对象

public class **Object**类 Object 是类层次结构的根类。每个类都使用 Object 作为超类。所有对象（包括数组）都实现这个类的方法。

Object o1 = 1;Object o2 = new Integer(1);Object o3 = new int[1];Object o4 = new Object[1];Object[] o5 = new Object[1];Object o6 = new Integer[1];

增强for循环

Can only iterate over an array or an instance of java.lang.Iterable

数组
实现了java.lang.Iterable接口的实例

class MyIterator implements Iterator<Object>{        private int curIndex; //记录当前迭代到了哪个位置        @Override        public boolean hasNext() {            return curIndex < index;        }        @Override        public Object next() {            return datas[curIndex++];        }    }

对象产生的

分配空间，对属性进行默认初始化

父类属性初始化

父类构造函数

子类属性初始化

子类构造函数被调用

class Person{    int age = 100;    Person(){        this(36);        print();    }    Person(int age){        this.age = age;    }    public void print(){        System.out.println(age);    }}class SuperPerson extends Person{    int age =200;    SuperPerson(){        this(12);        if(age == 18);            print();    }    SuperPerson(int age){        this.age = age;    }    @Override    public void print() {        System.out.println(age);    }}1.创建空间，默认初始化属性 0；2.父类属性初始化  age = 100 3.父类构造函数被调用 super.age = 36  this.age=04.子类属性初始化 this.age = 200;5.子类构造函数被调用 this.age = 12;

对象是怎么被回收的

    public static void main(String[] args){        Man man = new Man();        man = null;        System.gc();        try {            Thread.sleep(5000);        } catch (InterruptedException e) {            e.printStackTrace();        }    }

对象的克隆

基本数据类型的拷贝，拷贝的是值

引用数据类型的拷贝，拷贝的是地址

注意 clone() 方法是在Object中声明的，但是它的访问权限是 protected, 所以我们需要重写它，然后对它进行方法的覆盖

public class ObjectClone {    public static void main(String[] args) {        /*int[] aaa = {1,32,3,4,5,67};        int[] bbb = aaa.clone();        System.out.println(Arrays.toString(bbb));        bbb[1] = 100;        System.out.println(aaa[1]);*/        //二维数组的拷贝        /*int[] ccc[] = {{1,2,3},{4,5,6},{73,32}};        int[][] ddd = ccc.clone();        ddd[1][1] = 100;  //深拷贝， 浅拷贝        System.out.println(ccc[1][1]);*/        Cat cat = new Cat();        try {            Cat cloneCat = (Cat) cat.clone();//          cloneCat.mouse = (Mouse) cat.mouse.clone();            System.out.println(cloneCat.mouse.weight);            cat.mouse.weight--;            System.out.println(cloneCat.mouse.weight);        } catch (CloneNotSupportedException e) {            e.printStackTrace();        }    }}class Cat implements Cloneable {    Mouse mouse = new Mouse();    int age = 10;    //封装对象的拷贝    @Override    public Cat clone() throws CloneNotSupportedException {        Cat cloneCat = (Cat) super.clone();        cloneCat.mouse = (Mouse) this.mouse.clone();        return cloneCat;    }}class Mouse implements Cloneable {    int weight = 2;    @Override    public Object clone() throws CloneNotSupportedException {        return super.clone();    }}

双色球

红球：1~··33

篮球： 1~ 16

while(sets.size() < 6){  int random = (int) (Math.random()*33+1); // 0.0<=  <1.0  1<=r <34   sets.add(new MyNum("红球："+random));}

hashCode : 无序

hashCode — > equals (不可重复，无序)

    @Override    public boolean equals(Object obj) {        if(obj instanceof MyNum){            MyNum num = (MyNum) obj;            return num.ball.equals(this.ball);        }        return false;    }    @Override    public int hashCode() {        return this.ball.hashCode();    }

三人斗地主

要有一副牌

   private void initPuke(){        int index = 0;        //4.把牌存起来        for (int i = 0; i < 52; i++) {            //1.确定花色            char f = flower.charAt(i/13);            //2.确定牌号            int num = i%13 + 1; // 0~12  1-13            //3.转化牌号 A ，J...            switch (num) {                case 1: //A                    pukes[index++] = f+"A";                    break;                case 11: //J                    pukes[index++] = f+"J";                    break;                case 12: //Q                    pukes[index++] = f+"Q";                    break;                case 13: //K                    pukes[index++] = f+"K";                    break;                default: //2~9                    pukes[index++] = f+""+num;                    break;            }        }        pukes[index++]="小王";        pukes[index++]="大王";        print();    }

洗牌，发牌

随机取一个数

根据这个随机数，取到对应的牌

将牌的总量减少

将取到的牌后面所有的牌往前移动一位

    /**     * 随机取牌     */    public String getPuke(){        int random = (int) (Math.random()*pukeCount); // 0<= <54        String puke = pukes[random];        pukeCount--;        for (int i = random; i < pukeCount; i++) {            pukes[i] = pukes[i+1];        }        return puke;    }

三个玩家
玩家抓牌

对玩家手上牌进行排序

Arrays.sort(cards,0,number,new Comparator<String>() {   @Override   public int compare(String o1, String o2) {     if(o1.charAt(1) > o2.charAt(1)){       return 1;     }else{       return -1;     }   }});

抢地主：

有王
2个二
至少一个炸弹

public static int WANG = 1<<0; // 001public static int ER = 1<<1;  //010public static int ZHA = 1<<2; //100;public int isCallDizhu(){    int cardNumbers[] = new int[17];    for (int i = 0; i < cardNumbers.length; i++) {        String card = cards[i];        char num = card.charAt(1);        switch (num) {        case '王':            cardNumbers[0]++;            break;        case '1':            cardNumbers[10]++;            break;        case 'J':            cardNumbers[11]++;            break;          case 'Q':            cardNumbers[12]++;            break;          case 'K':            cardNumbers[13]++;            break;          case 'A':            cardNumbers[1]++;            break;          default: //2 - 9            cardNumbers[num - '0']++;            break;        }    }    int result = 0;    if(cardNumbers[0] > 0){  //判断是否有王        result |= WANG;  // 000 | 001 =  001;     }    if(cardNumbers[2] > 2){  //至少有两个二        result |= ER;    // 001 | 010 = 011;    }    for (int i = 0; i < cardNumbers.length; i++) {        if(cardNumbers[i] == 4){            result |= ZHA;        }    }    if(cardNumbers[0] == 2){  //判断双王        result |= ZHA;    }           return result;}

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