Starting from JDK1.5, a new function Foreach has been added, which is an abbreviation for a for loop to traverse data. The keyword used is still for, but the parameter format is different. Its detailed usage is:
for(Type e:collection){ //对变量e的使用}
Parameter description:
e: Its type Type is the type of the element value in the collection or array. This parameter is in the collection or array collection. of an element.
collections: The collection or array to be traversed, or it can be an iterator.
Use parameter e in the loop body, which is the element value that foreach obtains from the collection or array and iterator. The element value is traversed from beginning to end.
Specific example:
//必须导入util下面的这两个包:ArrayList,List; import java.util.ArrayList; import java.util.List; public class Foreach { public static void main(String[] arg){ List<String> list = new ArrayList<String>(); //创建List集合 list.add("abc"); //初始化list集合 list.add("def"); list.add("ghi"); list.add("jkl"); list.add("mno"); list.add("pqr"); System.out.print("Foreach遍历集合: \n\t"); for(String string:list){ //遍历List集合 System.out.print(string); //输出集合的元素值 } System.out.println(); String[] strs = new String[list.size()]; list.toArray(strs); //创建数组 System.out.println("Foreach遍历数组:\n\t"); for(String string: strs){ //遍历数组 System.out.print(string); //输出数组元素值 } } }
Summary:
Previous versions of JDK used for loops to traverse collections, arrays and iterators. This requires creating index variables, conditional expressions, which clutters the code and increases the chance of errors. And in each loop, the index variable or iterator will appear three times, giving two chances for error. And there will be some performance losses, its performance is slightly behind the foreach loop. Therefore, for traversing data collections, it is recommended to use a Foreach loop.
For more articles related to whether to use foreach loop or for loop to traverse an array in Java, please pay attention to the PHP Chinese website!

This article analyzes the top four JavaScript frameworks (React, Angular, Vue, Svelte) in 2025, comparing their performance, scalability, and future prospects. While all remain dominant due to strong communities and ecosystems, their relative popul

This article addresses the CVE-2022-1471 vulnerability in SnakeYAML, a critical flaw allowing remote code execution. It details how upgrading Spring Boot applications to SnakeYAML 1.33 or later mitigates this risk, emphasizing that dependency updat

Java's classloading involves loading, linking, and initializing classes using a hierarchical system with Bootstrap, Extension, and Application classloaders. The parent delegation model ensures core classes are loaded first, affecting custom class loa

The article discusses implementing multi-level caching in Java using Caffeine and Guava Cache to enhance application performance. It covers setup, integration, and performance benefits, along with configuration and eviction policy management best pra

Node.js 20 significantly enhances performance via V8 engine improvements, notably faster garbage collection and I/O. New features include better WebAssembly support and refined debugging tools, boosting developer productivity and application speed.

Iceberg, an open table format for large analytical datasets, improves data lake performance and scalability. It addresses limitations of Parquet/ORC through internal metadata management, enabling efficient schema evolution, time travel, concurrent w

This article explores methods for sharing data between Cucumber steps, comparing scenario context, global variables, argument passing, and data structures. It emphasizes best practices for maintainability, including concise context use, descriptive

This article explores integrating functional programming into Java using lambda expressions, Streams API, method references, and Optional. It highlights benefits like improved code readability and maintainability through conciseness and immutability


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

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

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

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools
