How to read input numbers and letters in Java? Use the Scanner class to read numbers (nextInt()) and strings (nextLine()). Use the BufferedReader class to read a line of text and parse the number (parseInt()). Use the Console class to read numbers (nextInt()) and strings (readLine()).
How to read entered numbers and letters in Java
There are various methods in Java to control The platform reads the numbers and letters entered by the user:
1. Scanner class
The Scanner class provides nextInt() and nextLine() methods for reading respectively. Numbers and strings.
import java.util.Scanner; public class ReadInput { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); // 读取数字 int number = scanner.nextInt(); // 读取字符串(包括空格) String inputString = scanner.nextLine(); } }
2. BufferedReader class
The BufferedReader class provides the readLine() method for reading a line of text.
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class ReadInput { public static void main(String[] args) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); // 读取数字 int number = Integer.parseInt(reader.readLine()); // 读取字符串(不包括换行符) String inputString = reader.readLine(); } }
3. Console class
The Console class (introduced in Java 11) provides a more concise way to read input.
import java.io.Console; public class ReadInput { public static void main(String[] args) { Console console = System.console(); // 读取数字 int number = console.reader().nextInt(); // 读取字符串(包括空格) String inputString = console.reader().readLine(); } }
Note:
- All methods block until the user enters data and presses Enter.
- For numeric input, make sure to check that the number is in the correct format, for example using the Integer.parseInt() or Integer.valueOf() methods.
The above is the detailed content of How to read input numbers and letters in java. For more information, please follow other related articles on 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

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.

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

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

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Zend Studio 13.0.1
Powerful PHP integrated development environment

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
