How to use scanner in java

In Java, the Scanner class is used to read input from an input source. Usage steps: Create Scanner object: new Scanner (input source) Read input: nextInt(), nextLine() and other methods Close Scanner object: close()

How to use the Scanner class in Java

Introduction:
In Java, the Scanner class is used to retrieve data from various input sources (such as console, file etc.) to read user input.

Syntax:

Scanner scanner = new Scanner(InputStream source);

Among them, source is an InputStream object representing the input source.

Usage:

1. Create Scanner object: Use new Scanner() constructor to create Scanner object. Pass the input source as a parameter to the constructor.
2. Read input: Use nextInt(), nextLine() and other methods to read specific types of data. These methods read a value from the input source and convert it to the appropriate type.
3. Close the Scanner object: Use the close() method to close the Scanner object to release system resources.

Example:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.println("输入您的年龄：");
        int age = scanner.nextInt();

        System.out.println("输入您的姓名：");
        String name = scanner.nextLine();

        System.out.println("您的年龄是：" + age);
        System.out.println("您的姓名是：" + name);

        scanner.close();
    }
}

Note:

• Make sure the input source is open, otherwise A NoSuchElementException exception will occur.
• When using the nextLine() method, it reads the entire line including the newline character.
• You must close the Scanner before using it to avoid resource leaks.

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