编程1

import java.util.*;abstract class Rodent//抽象类
{public abstract String findFood();//抽象方法public abstract String chewFood();
}
class Mouse extends Rodent
{public String findFood(){	return "大米";	}public String chewFood(){	return "Mouse"+"吃"+findFood();	}
}
class Gerbil extends Rodent
{public String findFood(){	return "种子";	}public String chewFood(){	return "Gerbil"+"吃"+findFood();	}
}
class Hamster extends Rodent
{public String findFood(){	return "坚果";	}public String chewFood(){	return "Hamster"+"吃"+findFood();	}
}
public class Main{public static void main(String[] args){Rodent[] rodents = new Rodent[3];rodents[0] = new Mouse();rodents[1] = new Gerbil();rodents[2] = new Hamster();System.out.println(rodents[0].chewFood());System.out.println(rodents[1].chewFood());System.out.println(rodents[2].chewFood());}
}

Mouse吃大米
Gerbil吃种子
Hamster吃坚果

编程2

用接口改造上一题，实现要求的所有功能

接口详细教程Java 接口 | 菜鸟教程 (runoob.com)

import java.util.*;interface Rodent
{public String findFood();public String chewFood();
}
class Mouse implements Rodent
{public String findFood(){	return "大米";	}public String chewFood(){	return "Mouse"+"吃"+findFood();	}
}
class Gerbil implements Rodent
{public String findFood(){	return "种子";	}public String chewFood(){	return "Gerbil"+"吃"+findFood();	}
}
class Hamster implements Rodent
{public String findFood(){	return "坚果";	}public String chewFood(){	return "Hamster"+"吃"+findFood();	}
}
public class Main{public static void main(String[] args){Rodent[] rodents = new Rodent[3];rodents[0] = new Mouse();rodents[1] = new Gerbil();rodents[2] = new Hamster();System.out.println(rodents[0].chewFood());System.out.println(rodents[1].chewFood());System.out.println(rodents[2].chewFood());}
}

Mouse吃大米
Gerbil吃种子
Hamster吃坚果

 

编程3

import java.util.*;interface Rodent
{public String findFood();public String chewFood();
}
interface Fly
{public String fly();
}
class Mouse implements Rodent
{public String findFood(){	return "大米";	}public String chewFood(){	return "Mouse"+"吃"+findFood();	}
}
class Gerbil implements Rodent
{public String findFood(){	return "种子";	}public String chewFood(){	return "Gerbil"+"吃"+findFood();	}
}
class Hamster implements Rodent
{public String findFood(){	return "坚果";	}public String chewFood(){	return "Hamster"+"吃"+findFood();	}
}
class Pteromyini implements Rodent,Fly
{public String findFood(){	return "野果";	}public String chewFood(){	return "Pteromyini"+"吃"+findFood();	}public String fly(){	return "会飞";	}
}
public class Main{public static void main(String[] args){Rodent[] rodents = new Rodent[4];rodents[0] = new Mouse();rodents[1] = new Gerbil();rodents[2] = new Hamster();rodents[3] = new Pteromyini();System.out.println(rodents[0].chewFood());System.out.println(rodents[1].chewFood());System.out.println(rodents[2].chewFood());System.out.println(rodents[3].chewFood()+" "+((Pteromyini)rodents[3]).fly());}
}

Mouse吃大米
Gerbil吃种子
Hamster吃坚果
Pteromyini吃野果 会飞

 

编程4

这道题给我看懵了，直接上AI

import java.util.Date;public class MaxFinder {// 实现找到Comparable对象数组中的最大元素的方法public static Comparable max(Comparable[] a) {if (a == null || a.length == 0) {return null; // 返回null表示数组为空或未初始化}Comparable max = a[0]; // 假设第一个元素是最大的for (int i = 1; i < a.length; i++) {if (max.compareTo(a[i]) < 0) {max = a[i]; // 发现更大的元素，更新max}}return max;}public static void main(String[] args) {// 测试字符串数组String[] strings = {"apple", "orange", "banana", "zoo", "cherry", "date", "fig", "grape", "honeydew", "kiwi"};System.out.println("最大的字符串: " + max(strings));// 测试整数数组Integer[] integers = {20, 35, 1, 67, 55, 23, 99, 18, 42, 88};System.out.println("最大的整数: " + max(integers));// 测试日期数组Date[] dates = new Date[10];for (int i = 0; i < dates.length; i++) {// 创建从现在开始的不同天的日期dates[i] = new Date(System.currentTimeMillis() + i * 24 * 60 * 60 * 1000);}System.out.println("最新的日期: " + max(dates));}
}

最大的字符串: zoo
最大的整数: 99
最新的日期: Mon Apr 22 21:35:46 CST 2024