【java】遍历list集合的三种方式，iterator遍历list集合

深藏阁楼爱情的钟 2024-03-27 14:23 131阅读 0赞

#### 目录 ####

*  1.现有list集合如下：
 *  1. for循环遍历
 *  2.增强for循环
 *  3.iterator遍历

## 1.现有list集合如下： ##

public class main {
        
    
        public class UserInfo{
        
            private int id;
            private String userName;
            private Integer age;
            private String userCode;
        }
        
        @Test
        public void test(){
        
    
            UserInfo user1 = new UserInfo();
            user1.id = 1;
            user1.userName = "hoshi";
            user1.age = 27;
            UserInfo user2 = new UserInfo();
            user2.id = 2;
            user2.userName = "dk";
            user2.age = 26;
            UserInfo user3 = new UserInfo();
            user3.id = 3;
            user3.userName = "SEUNGKWAN";
            user3.age = 25;
            UserInfo user4 = new UserInfo();
            user4.id = 4;
            user4.userName = "dino";
            user4.age = 24;
    
            List<UserInfo> lst = Arrays.asList(user1, user3, user4, user2);
    	}
    }

## 1. for循环遍历 ##

for(int i = 0; i < lst.size(); i++){
        
    	System.out.println("id:" + lst.get(i).id + ",\tname:" + lst.get(i).userName+"\n");
    }

![在这里插入图片描述][1107bd0a512141f680195cd803ff0996.png_pic_center]

## 2.增强for循环 ##

for(UserInfo x : lst){
        
    	System.out.println("id:" + lst.get(i).id + ",\tuserName:" + lst.get(i).userName+"\n");
    }

![在这里插入图片描述][ba9ece4165f6415aa698a5d656814062.png_pic_center]

## 3.iterator遍历 ##

Iterator<UserInfo> iterator = lst.iterator();
            while(iterator.hasNext()){
        
                UserInfo next = iterator.next();
                System.out.println("id:"+next.id+", \tname:"+next.userName+", \tage:"+next.age);
            }

![在这里插入图片描述][3334212aaaef4fa79f4ff88fd6a44dc0.png_pic_center]  
**注意：** 当需要使用iterator进行第二次循环时，需要给iterator重新赋值。

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![在这里插入图片描述][e81d18b8128947128bdf1be7ee29d647.jpeg_pic_center]

[1107bd0a512141f680195cd803ff0996.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/27/5d2131a04a2a4ea5b53c02cff1bbb9a4.png
[ba9ece4165f6415aa698a5d656814062.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/27/7e9490d13d114a8e940d213ab2a25bf2.png
[3334212aaaef4fa79f4ff88fd6a44dc0.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/27/22dc98ae89574b5588a9e823b74a7cf2.png
[e81d18b8128947128bdf1be7ee29d647.jpeg_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/27/f3f7640f214f431294ee31216fc3e26a.png