0920作业-----越练越熟，比昨晚快了2个小时~~~

  1 public class Text1{

    public static void main(String[] args){
        Outter o=new Outter();
        //第一题-----上面一句代码是外部类的对象实例化
        System.out.println("第一题：");
        Outter.B b=o.new B();
        b.showA();
        b.showB();
        //第二题
        System.out.println("第二题：");
        Outter.Staff s=o.new Staff();
        s.name="李四";
        System.out.println(s.name);
        //第三题-----多态---1 方法重载 2 方法重写 3 对象多态，这里是对象多态
        System.out.println("第三题：");
        Outter.Car car=o.new Aodi();
        car.changeSpeed();
        car=o.new Benchi();
        car.changeSpeed();
        //第四题-----多态
        System.out.println("第四题：");
        Outter.Rect r=o.new PlaintRect(20,10,10,10);
        System.out.println("周长为："+r.perimeter());
        System.out.println("周长为："+r.area());
        System.out.println("坐标"+(r.isInside(10,20)==true?"有效":"无效"));
    }
}
//外部类
class Outter{
    //第一题 
    //父类A
    class A{
        public void showA(){
            char a[]=new char[26];
            for(int i=0,b='a';i<a.length;i++,b++){
                a[i]=(char)b;
                System.out.print(a[i]+" ");                
            }
            System.out.println();
        }
    }
    //子类B继承父类
    class B extends A{
        public void showB(){
            char a[]=new char[26];
            for(int i='A';i<a.length+'A';i++){
                a[i-'A']=(char)i;
                System.out.print(a[i-'A']+" ");
            }
            System.out.println();
        }    
    }
    //第二题
    //父类Penson
    class Penson{
        protected String name;
        protected String address;
        protected String telphone;
        protected String mail;
    }
    //Penson的子类Employee
    class Employee extends Penson{
        protected String office;
        protected double wage;
        protected String hiredate;
    }
    //Employee的子类Faculty
    class Faculty extends Employee{
        protected String degree;
        protected String level;
    }
    //Employee的子类Staff
    class Staff extends Employee{
        protected String duty;
    }
    //第三题
    //主类Car
    class Car{
        protected String pinPai;
        protected void changeSpeed(){
            System.out.println("呜呜呜......");
        }
    }
    //子类Aodi继承Car
    class Aodi extends Car{
        private double price;
        private String xingHao;
        public double getPrice(){
            return price;
        }
        public String getXingHao(){
            return xingHao;
        }
        public void changeSpeed(){
            System.out.println("变速卡卡卡......");
        }
    }
    //子类Benchi继承Car
    class Benchi extends Car{
        private double price;
        private String xingHao;
        public double getPrice(){
            return price;
        }
        public String getXingHao(){
            return xingHao;
        }
        public void changeSpeed(){
            System.out.println("变速嘟嘟嘟......");
        }
    }
    //第四题
    //矩形类Rect
    abstract class Rect{
        protected int width;
        protected int height;
        Rect(){
            width=10;
            height=10;
        }
        Rect(int width,int height){
            this.width=width;
            this.height=height;
        }
        protected int area(){
            return width*height;
        }
        protected int perimeter(){
            return 2*(width+height);
        }
        public abstract boolean isInside(int x,int y);
    }
    //带坐标的PlaintRect类继承自Rect
    class PlaintRect extends Rect{
        private int startX;
        private int startY;
        PlaintRect(){
            this(0,0,0,0);
        }
        PlaintRect(int width,int height,int startX,int startY){
            super(width,height);
            this.startX=startX;
            this.startY=startY;
        }
        public void setStartX(int startX){
            this.startX=startX;
        }
        public void setStartY(int startY){
            this.startY=startY;
        }
        public int getStartX(){
            return startX;
        }
        public int getStartY(){
            return startY;    
        }
        public boolean isInside(int x,int y){
            return x>=startX&&x<=(startX+width)&&y<startY&&y>=(startY-height);
        }
    }
}