package com.ykmimi.javabianchengsixiang;/** * 形状的继承 随机形状生成器 * @author ukyor */import java.util.Random;class Shape{    public void draw() {}    //擦除 erase    public void erase() {}}//类 圆形 继承自基类 Shape形状class Circle extends Shape{    public void draw() {System.out.println("Circle.draw()");}    public void erase() {System.out.println("Circle.erase()");}}//类 矩形 继承自基类 Shape形状class Square extends Shape{    public void draw() {System.out.println("Square.draw()");};    public void erase() {System.out.println("Square.erase)");};}//类 三角形 继承自基类 Shape形状class Triangle extends Shape{    public void draw() {System.out.println("Triangle.draw()");};    public void erase() {System.out.println("Triangle.erase)");};}//随机形状生成器class RandomShapeGenerator{    //随机数 (0~(30~110))~(120/200)    private static int randomNumber = (int)((Math.random()*(30+Math.random()*80))+Math.random()*90);     private Random rand = new Random(randomNumber);    public Shape next() {        switch(rand.nextInt(3)) {            default:            case 0 : return new Circle();            case 1 : return new Square();            case 2 : return new Triangle();        }    }    public void print() {        System.out.println(randomNumber);    }    }public class Shapes {    //创建静态的随机形状生成器的对象 gen    private static RandomShapeGenerator gen = new RandomShapeGenerator();    public static void main(String[] args) {        //声明形状数组 s 长度为 9 ;        Shape[] s = new Shape[9];        for(int i=0;i

 

 

 

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package 随机数;/** * 理解随机数,随机数组 * @author ukyozq */import java.util.Random;public class RandomNumberOrArray{    public static void main(String[] args) {            //声明随机数int rand.范围[0,98]        int rand = (int)(Math.random()*99);        //输出,每次运行会输出不同的数字.        System.out.println(rand);                //理所当然我们想到要用数组装入更多随机数        int[] randArray = new int[10];        for(int i=0;i