HashMap 存储自定义类型键值

package com.oracle.demo01;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class Demo01 {
    public static void main(String[] args) {
        //HashMap   存储自定义类型键值
        HashMap<String, String> map=new HashMap<String, String>();

        //存值
        map.put("张三", "123");
        map.put("小红", "123");
        map.put("张三", "456");

        //删除
        //map.remove("张三");

        //取值
        //System.out.println(map.get("张三"));


        //遍历
        //1.keySet+增强for 遍历
        //获取所有key所在的Set集合
        Set<String> set =map.keySet();
        for (String key : set) {
            System.out.println(map.get(key));
        }

        //2.keySet+iterator 遍历
        Iterator<String> it=set.iterator();
        while (it.hasNext()) {
            String k=it.next();
            String value=map.get(k);
            //打印key+value
            System.out.println(k+" "+value);

        }
    }
}

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