题目一:

解法一:元素不变,索引随机
package com.itheima.a06test;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Random;
public class Test1 {
public static void main(String[] args) {
//1.创建集合(因为不知道有多少个学生,所以用集合)
ArrayList<String> list = new ArrayList<>();
//2.添加元素
Collections.addAll(list, "范闲", "范建", "范统", "杜子腾", "杜琦燕", "宋合泛", "侯笼藤", "朱益群", "朱穆朗玛峰", "袁明媛");
//3.定义随机器
Random r = new Random();
int index = r.nextInt(list.size());
/*list.size()代表list集合的长度,此时集合长度为10,
所以随机数据的范围为[0,10)即[0,9]*/
/