1：练习

image.png :::info 最后输出：9 red 100 red
注意：color是静态属性 :::

2：

image.png

  1. public class HomeWork2 {
  2.     public static void main(String[] args) {
  3.         System.out.println(Frock.getNextNum());
  4.         System.out.println(Frock.getNextNum());
  6.         Frock frock = new Frock();
  7.         System.out.println(frock.getSerialNumber());
  9.         Frock frock1 = new Frock();
  10.         System.out.println(frock1.getSerialNumber());
  12.         Frock frock2 = new Frock();
  13.         System.out.println(frock2.getSerialNumber());
  14.     }
  15. }
  17. class Frock{
  18.     private static int currentNum = 100000;
  19.     private int serialNumber;
  21.     public Frock() {
  22.         this.serialNumber = getNextNum();
  23.     }
  25.     public static int getNextNum(){
  26.         return currentNum += 100;
  27.     }
  29.     public int getSerialNumber() {
  30.         return serialNumber;
  31.     }
  32. }

3：

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  1. public class HomeWork3 {
  2.     public static void main(String[] args) {
  3.         Animal cat = new cat();
  4.         Animal dog = new dog();
  5.         cat.shout();
  6.         dog.shout();
  7.     }
  8. }
  9. abstract class Animal{
  10.     abstract public void shout();
  11. }
  12. class cat extends Animal{
  13.     @Override
  14.     public void shout() {
  15.         System.out.println("小猫叫");
  16.     }
  17. }
  18. class dog extends Animal{
  19.     @Override
  20.     public void shout() {
  21.         System.out.println("小狗叫");
  22.     }
  23. }

4：

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  1. package Date0821.HomeWork;
  2. public class HomeWork4 {
  3.     public static void main(String[] args) {
  4.         Cellphone cellphone = new Cellphone();
  5.         //匿名内部类是
  6.         /*
  7.             new Calculate() {
  8.                 @Override
  9.                 public int Work(int n1, int n2) {
  10.                     System.out.println(n1 + n2);
  11.                     return n1 + n2;
  12.                 }
  13.             }  同时也是一个对象
  14.         */
  15.         cellphone.TestWork(new Calculate() {
  16.             @Override
  17.             public int Work(int n1, int n2) {
  19.                 System.out.println(n1 + n2);
  20.                 return n1 + n2;
  21.             }
  22.         },4,5);
  24.         cellphone.TestWork(new Calculate() {
  25.             @Override
  26.             public int Work(int n1, int n2) {
  27.                 System.out.println(n1 + n2);
  28.                 return n1 * n2;
  29.             }
  30.         },4,5);
  31.     }
  32. }
  33. interface Calculate{
  34.     //work方法完成计算，具体计算方法交给匿名内部类
  35.     public int Work(int n1 ,int n2);
  36. }
  37. class Cellphone{
  38.     public void TestWork (Calculate calculate,int n1,int n2){
  39.         int result =  calculate.Work(n1,n2);
  40.         System.out.println("运算结束,结果为"+ result);
  41.     }
  42. }

5：

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  1. public class HomeWork5 {
  2.     public static void main(String[] args) {
  3.         A a = new A();
  4.         //通过方法创建成员内部类，然后调用方法
  5.         a.Get().show();
  7.         //创建成员内部类
  8.         A.B b = a.new B();
  9.         b.show();
  10.     }
  11. }
  13. class A {
  14.     private String name = "A";
  16.     class B{
  17.         private final String name = "B";
  18.         public void show(){
  19.             System.out.println(A.this.name);
  20.             System.out.println(B.this.name);
  21.         }
  22.     }
  23.     public B Get(){
  24.         B b = new B();
  25.         return b;
  26.     }
  27. }
  1. public class HomeWork5 {
  2.     public static void main(String[] args) {
  3.         A a = new A();
  4.         a.Inner();
  5.     }
  6. }
  7. class A {
  8.     private String name = "A";
  10.     public void Inner(){
  11.         class B{
  12.             private final String name = "B";
  13.             public void show(){
  14.                 System.out.println(A.this.name);
  15.                 System.out.println(B.this.name);
  16.             }
  17.         }
  18.         B b = new B();
  19.         b.show();
  20.     }
  21. }

6：

、image.png

  1. package Date0821.HomeWork;
  3. /**
  4.  * 作者：sakura
  5.  * 日期：2022年08月21日 22:09
  6.  */
  7. public class HomeWork6 {
  9.     public static void main(String[] args) {
  10.         //正常情况下：船每次都会换，而马这个对象是不变的
  11.         //初始化人的时候会给他分配一个交通工具，但是又不能浪费
  12.         Person sakura = new Person("Sakura", factory.getHorse());
  13.         sakura.Commen();
  14.         sakura.River();
  15.         sakura.River();
  16.         sakura.mountain();
  17.     }
  18. }
  20. interface  Vehicles{
  22.     public void work();
  24. }
  25. class horse implements Vehicles{
  27.     @Override
  28.     public void work() {
  29.         System.out.println("用马");
  30.     }
  31. }
  32. class Boat implements Vehicles{
  34.     @Override
  35.     public void work() {
  36.         System.out.println("用船");
  37.     }
  38. }
  40. class factory{
  41.     //马每次只需要一匹
  42.      public static horse horse =  new horse();
  43.      //饿汉式
  45.     //这里使用static就不用创建工厂对象了
  46.     public static horse getHorse(){
  47.         return horse;
  48.     }
  49.     public static Boat getBoat(){
  50.         return new Boat();
  51.     }
  53. }
  55. class Person{
  57.     private String name;
  58.     private Vehicles vehicles;
  60.     public void setVehicles(Vehicles vehicles) {
  61.         this.vehicles = vehicles;
  62.     }
  64.     public Person(String name, Vehicles vehicles) {
  65.         this.name = name;
  66.         this.vehicles = vehicles;
  67.     }
  68.     public void River(){
  69.         //这个判断条件有两个含义：
  70.         //1: 判断这个交通工具不是船
  71.         //2: 判断这个交通功能为空
  72.         if ( !(this.vehicles instanceof  Boat) ){
  73.             this.vehicles = factory.getBoat();
  74.         }
  75.         this.vehicles.work();
  78.     }
  79.     public void Commen(){
  80.         if (!(this.vehicles instanceof  horse)){
  81.             this.vehicles =  factory.getHorse();
  82.         }
  83.         this.vehicles.work();
  84.     }
  86.     //火焰山只需要飞过一次，所以用匿名内部类
  87.     public void mountain(){
  88.          new Vehicles() {
  89.             @Override
  90.             public void work() {
  91.                 System.out.println("飞过火焰山");
  92.             }
  93.         }.work();
  94.     }
  96. }

7：

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  1. public class HomeWork7 {
  2.     public static void main(String[] args) {
  3.         Car car = new Car();
  4.         Car.Air air = car.new Air();
  5.         air.flow(60);
  6.         air.flow(30);
  7.         air.flow(-30);
  8.     }
  9. }
  10. class Car{
  11.     private double temperature;
  13.     class Air{
  14.         public void flow(double temperature){
  15.             if (temperature > 40) {
  16.                 System.out.println("吹冷风");
  17.             }else if (temperature < 0){
  18.                 System.out.println("吹热风");
  19.             }else {
  20.                 System.out.println("啥都不干");
  21.             }
  22.         }
  23.     }
  24.     //也可以通过getAir返回对象,在加一个有参构造器实现
  25.     //  Car car = new Car(60);
  26.     //  car.getAir.flow();
  27.     public Air getAir(){
  28.         return new Air();
  29.     }
  31. }

8：

image.png

  1. public class HomeWork8 {
  2.     public static void main(String[] args) {
  3.         Color.RED.show();
  4.         Color.GREEN.show();
  5.     }
  6. }
  7. interface T{
  8.     public void show();
  9. }
  10. enum Color implements T{
  12.     RED(255,0,0),
  13.     BLUE(0,0,255),
  14.     BLACK(0,0,0),
  15.     YELLOW(255,255,0),
  16.     GREEN(0,255,0);
  17.     private int REDValue;
  18.     private int GREENValue;
  19.     private int BLUeValue;
  20.     Color(int REDValue, int GREENValue, int BLUeValue) {
  21.         this.REDValue = REDValue;
  22.         this.GREENValue = GREENValue;
  23.         this.BLUeValue = BLUeValue;
  24.     }
  25.     @Override
  26.     public void show() {
  27.         System.out.println("(" + REDValue+","+GREENValue+","+ +BLUeValue+")");
  28.     }
  29. }