如何在 Java 中读取标准输入?
javaobject oriented programmingprogramming更新于 2024/5/10 16:04:00
标准输入 (stdin) 可以用 Java 中的 System.in 表示。System.in 是 InputStream 类的一个实例。这意味着它的所有方法都适用于字节，而不是字符串。要从键盘读取任何数据，我们可以使用 Reader 类 或 Scanner 类。
示例 1
import java.io.*;
public class ReadDataFromInput {
public static void main (String[] args) {
int firstNum, secondNum, result;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); try {
System.out.println("Enter a first number:");
firstNum = Integer.parseInt(br.readLine());
System.out.println("Enter a second number:");
secondNum = Integer.parseInt(br.readLine());
result = firstNum * secondNum;
System.out.println("The Result is: " + result);
} catch (IOException ioe) {
System.out.println(ioe);
}
}
}
输出
Enter a first number: 15 Enter a second number: 20 The Result is: 300
Example2
import java.util.*;
public class ReadDataFromScanner {
public static void main (String[] args) {
int firstNum, secondNum, result;
Scanner scanner = new Scanner(System.in); System.out.println("Enter a first number:");
firstNum = Integer.parseInt(scanner.nextLine());
System.out.println("Enter a second number:");
secondNum = Integer.parseInt(scanner.nextLine());
result = firstNum * secondNum;
System.out.println("The Result is: " + result);
}
}
输出
Enter a first number: 20 Enter a second number: 25 The Result is: 500
