HashMap：无序，不重复，无索引

HashMap小练习：

import java.text.ParseException;
import java.util.*;
import java.util.function.BiConsumer;
import java.util.function.Consumer;

import static java.lang.Math.abs;

public class Test3 {
        public  static void main(String[] args) {
            //定义数组，存储4个景点
            String[] arr={"A","B","C","D"};
            ArrayList<String> list=new ArrayList<>();
            Random r=new Random();
            for (int i = 0; i < 80; i++) {
                int i1 = r.nextInt(arr.length);
                list.add(arr[i1]);
            }
            HashMap<String,Integer> hashMap=new HashMap<>();
            for (String name : list) {
                //判断当前投票的景点是否存在
                if(hashMap.containsKey(name)){
                    //存在
                    int count = hashMap.get(name);

                    count++;
                    hashMap.put(name,count);


                }else {//不存在
                    hashMap.put(name,1);

                }

            }
            //求最大值
            int max=0;
            Set<Map.Entry<String, Integer>> entries = hashMap.entrySet();
            //判断哪个景点的次数跟最大值一样，如果一样，打印出来
            for (Map.Entry<String, Integer> entry : entries) {
                int count = entry.getValue();
                if(count>max){
                    max=count;
                }
            }
            System.out.println(max);

        }


        }