集合的练习

import java.util.*;

public class text {
    public static void main(String[] args) {
        //第一种实现方式
        List<String> list=new ArrayList<>();
        Collections.addAll(list,"张三","李四","王五","赵六","前妻");
        Random random=new Random();
        int i = random.nextInt(list.size());
        String s=list.get(i);
        System.out.println(s);
        //第二种实现方式
        Collections.shuffle(list);
        System.out.println(list.get(0));

    }
}

import java.util.ArrayList;
import java.util.Collections;
import java.util.Random;

public class text2 {
    public static void main(String[] args) {
        //创建集合
        ArrayList<Integer> arrayList=new ArrayList<>();
        //添加数据
        Collections.addAll(arrayList,1,1,1,1,1,1,1);
        Collections.addAll(arrayList,0,0,0);
        //打乱集合中的数据
        Collections.shuffle(arrayList);
        //从集合中随机抽取0或1
        Random random=new Random();
        int index = random.nextInt(arrayList.size());
        int number=arrayList.get(index);
        //创建两个集合分别储存男生和女生的名字
        ArrayList<String> boyList=new ArrayList<>();
        ArrayList<String> girlList=new ArrayList<>();
        //添加数据
        Collections.addAll(boyList,"刘宇坚","李进","许德俊","周文杰","张宇坤");
        Collections.addAll(boyList,"邱静","张芊","熊伟仪");
        //根据0和1从集合中取值
        if (number==1){
            int bindex=random.nextInt(boyList.size());
            System.out.println(boyList.get(bindex));
        }else {
            int gindex=random.nextInt(boyList.size());
            System.out.println(boyList.get(gindex));
        }
    }
}