Iterator in Java is a tool used to traverse collections. Usage methods include: Obtaining an Iterator: Use the iterator() method of the Collection interface. Loop through the collection: use hasNext() to check if the next element exists, use next() to get the current element and move to the next element.
Usage of Iterator in Java
What is Iterator?
The Iterator interface is a tool in the Java programming language for traversing collections. It provides a set of methods that allow the programmer to access each element in the collection sequentially.
Usage of Iterator:
-
Get Iterator:
- Use Collection interface
iterator()
Method gets the Iterator of the collection.
- Use Collection interface
-
Loop through the collection:
- Use the
hasNext()
method to check whether the Iterator still exists The next element. - If there is, use the
next()
method to get the current element and move to the next element.
- Use the
Sample code:
// 创建一个字符串集合 Set<String> names = new HashSet<>(); names.add("Alice"); names.add("Bob"); names.add("Carol"); // 获取集合的 Iterator Iterator<String> iterator = names.iterator(); // 循环遍历集合 while (iterator.hasNext()) { String name = iterator.next(); System.out.println(name); }
Advantages:
- Flexibility: Iterator can be used to traverse various types of collections, including List, Set and Map.
- Sequential traversal: Iterator provides an ordered way to traverse the elements in a collection.
- Avoid concurrent modifications: Using Iterator can avoid concurrent modifications to the collection when traversing the collection, thereby preventing data corruption.
Note:
Iterator is a read-only interface and cannot be used to modify elements in the collection. If you need to modify the collection, you need to use other methods, such as List.set()
or Map.put()
.
The above is the detailed content of How to use iterator in java. For more information, please follow other related articles on the PHP Chinese website!

Discussion on instruction reordering under single thread in Java In Java programming, instruction reordering is a common topic. Instruction reordering refers to the compiler and processor...

Create periodic repeating calendar events in Outlook This article will explore how to create daily or weekly repeating calendar events in Outlook using Java code. carry...

Tomcat starts Servlet error check When troubleshooting. When deploying Servlet application, Tomcat failed to start and reported java.lang.IllegalStateException:...

Discussion on ZipInputStream character set settings Many developers use ZipInputStream to decompress zip compressed packages containing Chinese file names or folder names, �...

Implementing the retry strategy using SpringWebFlux in building an LLM...

JDBC...

Android...

How to avoid repeated execution of timed tasks in SpringBoot multi-node environment? In Spring...


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

Zend Studio 13.0.1
Powerful PHP integrated development environment

SublimeText3 English version
Recommended: Win version, supports code prompts!

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool