Java语言多态课后归档作业

class Mammal{}
class Dog extends Mammal {}
class Cat extends Mammal{}
public class TestCast
{
    public static void main(String args[])
    {
        Mammal m;
        Dog d=new Dog();
        Cat c=new Cat();
        m=d;
        //d=m;  出错
        d=(Dog)m;
        //d=c;  出错
        //c=(Cat)m;
    }
}

public class ParentChildTest {
    public static void main(String[] args) {
        Parent parent=new Parent();
        parent.printValue();
        Child child=new Child();
        child.printValue();
        
        parent=child;
        parent.printValue();
        
        parent.myValue++;
        parent.printValue();
        
        ((Child)parent).myValue++;
        parent.printValue();
        
    }
}

class Parent{
    public int myValue=100;
    public void printValue() {
        System.out.println("Parent.printValue(),myValue="+myValue);
    }
}
class Child extends Parent{
    public int myValue=200;
    public void printValue() {
        System.out.println("Child.printValue(),myValue="+myValue);
    }
}

//ATM

//LANGLANGBAI,2016.11.18

import java.util.Scanner;

public class ATM1 {

   private String Account;

   private String mima;

   private String name;

   private String Date;

   private double YuE;

   ATM1(String a,String b,String c,String d,double e){

       Account = a;

       mima = b;

       name = c;

       Date = d;

       YuE = e;

   }

   void setYuE(double m)

   {

       YuE = m;

   }

   void setMima(String a){

       mima = a;

   }

   String getName(){return name;}

   String getMima(){return mima;}

   double getYue(){return YuE;}

   static void meno1(){

       System.out.println("1、存款\n2、取款\n3、转账汇款\n4、修改密码\n5、查询余额\n0、退出");

   }

 

    public static void main(String[] args) {

       // TODO Auto-generated method stub

       Scanner in1 = new Scanner(System.in);

       Scanner in2 = new Scanner(System.in);

       Scanner in3 = new Scanner(System.in);

       Scanner in4 = new Scanner(System.in);

       Scanner in5 = new Scanner(System.in);

       ATM1[] a = new ATM1[20];

       int num=1;

       int j;

       a[0] = new ATM1("12345678912","123456","白浪浪","2016\11\17",1000);

        System.out.println("请插卡：\n插卡成功");

        System.out.println("请输入密码：");

        String mi = in1.next();

        for(int i=0;i<num;i++)

        {

           if(mi .equals(a[i].getMima()) )

              {

              System.out.println("密码 正确");

               meno1();

              double qian_num;

               j=in2.nextInt();

              while(j!=0)

              {

                if(j==1)

                {

                  System.out.println("请放入钞票：");

                  qian_num=in3.nextDouble();

                  a[i].setYuE(a[i].getYue()+qian_num);

                  System.out.println("存钱成功");

                }

                if(j==2)

                {

                    System.out.println("请输入要进取款的金额：1、100 2、500  3、1000 4、1500 5、2000 6、5000 7、其他 8、退卡");

                    int k;

                    k=in2.nextInt();

                    if(k==1)

                       a[i].setYuE(a[i].getYue()-100);

                    else if(k==2)

                       a[i].setYuE(a[i].getYue()-500);

                    else if(k==3)

                       a[i].setYuE(a[i].getYue()-1000);

                    else if(k==4)

                       a[i].setYuE(a[i].getYue()-1500);

                    else if(k==5)

                       a[i].setYuE(a[i].getYue()-2000);

                    else if(k==6)

                       a[i].setYuE(a[i].getYue()-5000);

                    else if(k==7)

                    {qian_num = in4.nextDouble();

                    a[i].setYuE(a[i].getYue()-qian_num);}

                }

                if(j==3)

                {

                    System.out.println("请输入要转账的账号 ：");

                    String a1;

                    a1 = in5.next();

                    System.out.println("请输入要转账的金额 ：");

                    String a2;

                    a2 = in5.next();

                    System.out.println("转账成功！ ：");

                }

                if(j==4)

                {

                    System.out.println("请输入修改后的密码 ：");

                    String a1;

                    a1 = in5.next();

                    a[i].setMima(a1);

                }

                if(j==5)

                {

                    System.out.println("余额  ："+a[i].getYue());

                }

                meno1();

                j=in2.nextInt()；
                }

              }
           else if(i == num)
              System.out.println("密码错误，该卡锁定。");
        }
        in1.close();
        in2.close();
        in3.close();
        in4.close();
        in5.close();
    }
}