[{"createTime":1735734952000,"id":1,"img":"hwy_ms_500_252.jpeg","link":"https://activity.huaweicloud.com/cps.html?fromacct=261f35b6-af54-4511-a2ca-910fa15905d1&utm_source=V1g3MDY4NTY=&utm_medium=cps&utm_campaign=201905","name":"华为云秒杀","status":9,"txt":"华为云38元秒杀","type":1,"updateTime":1735747411000,"userId":3},{"createTime":1736173885000,"id":2,"img":"txy_480_300.png","link":"https://cloud.tencent.com/act/cps/redirect?redirect=1077&cps_key=edb15096bfff75effaaa8c8bb66138bd&from=console","name":"腾讯云秒杀","status":9,"txt":"腾讯云限量秒杀","type":1,"updateTime":1736173885000,"userId":3},{"createTime":1736177492000,"id":3,"img":"aly_251_140.png","link":"https://www.aliyun.com/minisite/goods?userCode=pwp8kmv3","memo":"","name":"阿里云","status":9,"txt":"阿里云2折起","type":1,"updateTime":1736177492000,"userId":3},{"createTime":1735660800000,"id":4,"img":"vultr_560_300.png","link":"https://www.vultr.com/?ref=9603742-8H","name":"Vultr","status":9,"txt":"Vultr送$100","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":5,"img":"jdy_663_320.jpg","link":"https://3.cn/2ay1-e5t","name":"京东云","status":9,"txt":"京东云特惠专区","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":6,"img":"new_ads.png","link":"https://www.iodraw.com/ads","name":"发布广告","status":9,"txt":"发布广告","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":7,"img":"yun_910_50.png","link":"https://activity.huaweicloud.com/discount_area_v5/index.html?fromacct=261f35b6-af54-4511-a2ca-910fa15905d1&utm_source=aXhpYW95YW5nOA===&utm_medium=cps&utm_campaign=201905","name":"底部","status":9,"txt":"高性能云服务器2折起","type":2,"updateTime":1735660800000,"userId":3}]
<>Set集合概述和特点
*
Set集合概述
Set作为Collection集合的子接口，没有新增的功能，Collection集合可用的功能Set集合也可以用。
*
Set集合特点
Set集合存储的元素是无序的，而且不允许存储重复的元素，每当有新的元素存入的时候，Set集合会先去过滤，如果发现和集合中现有元素出现重复，就不再允许添加
* 不包含重复元素的集合
* 没有带索引的方法，所以不能使用普通的for循环遍历
*
存储字符串并遍历
package com.gather.set; import java.util.HashSet; import java.util.Set; public
class SetDemo01 { public static void main(String[] args) { //创建集合对象 Set<String>
set=new HashSet<String>(); //添加元素 set.add("hello"); set.add("world"); set.add(
"java"); //不包含重复元素 set.add("world"); //遍历 for (String s:set){ System.out.println
(s); } } }
HashSet实现了Set接口，创建对象时使用HashSet创建，它是java.util包下，使用时需要导包，HashSet对集合的迭代顺序不作任何保证是无序的
