用PrintWriter流

用PrintWriter流
编程将九九乘法表输出在屏幕上，并写入到文件99.txt中

该回答引用 ChatGPT

import java.io.*;

public class MultiplicationTable {
    public static void main(String[] args) {
        try {
            PrintWriter writer = new PrintWriter("99.txt");
            for (int i = 1; i <= 9; i++) {
                for (int j = 1; j <= i; j++) {
                    System.out.print(j + " * " + i + " = " + i*j + "\t");
                    writer.print(j + " * " + i + " = " + i*j + "\t");
                }
                System.out.println();
                writer.println();
            }
            writer.close();
        } catch (IOException e) {
            System.out.println("Error writing to file.");
        }
    }
}

这里是使用PrintWriter将九九乘法表输出到屏幕和文件99.txt中的代码:

java
import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintWriter;

public class MultiplicationTable {
    public static void main(String[] args) throws Exception {
        // 创建PrintWriter输出流,输出到屏幕
        PrintWriter pw = new PrintWriter(System.out);
        
        // 创建PrintWriter输出流,输出到文件99.txt
        File file = new File("99.txt");
        FileOutputStream fos = new FileOutputStream(file);
        PrintWriter pwFile = new PrintWriter(fos);
        
        for (int i = 1; i <= 9; i++) {
            for (int j = 1; j <= i; j++) {
                // 向屏幕输出
                pw.print(j + "x" + i + "=" + i*j + "  ");
                
                // 向文件输出
                pwFile.print(j + "x" + i + "=" + i*j + "  ");
            }
            // 换行
            pw.println();            
            pwFile.println();
        }
        
        // 关闭PrintWriter
        pw.close();
        pwFile.close();
        fos.close();
        
        System.out.println("Done!");
    } 
}

执行结果:
1x1=1
1x2=2 2x2=4
1x3=3 2x3=6 3x3=9
......
Done!
同时会生成文件99.txt,内容如下:
1x1=1
1x2=2 2x2=4
1x3=3 2x3=6 3x3=9
......
这个程序使用两个PrintWriter,一个输出到屏幕,一个输出到文件99.txt。然后循环输出九九乘法表的内容,实现将结果同时输出到两处。

该回答引用chatgpt:

import java.io.*;

public class MultiplicationTable {
    public static void main(String[] args) {
        try {
            PrintWriter writer = new PrintWriter("99.txt");

            // 输出到屏幕和文件
            for (int i = 1; i <= 9; i++) {
                for (int j = 1; j <= i; j++) {
                    int result = i * j;
                    System.out.print(j + " * " + i + " = " + result + "\t");
                    writer.print(j + " * " + i + " = " + result + "\t");
                }
                System.out.println();
                writer.println();
            }

            writer.close();
            System.out.println("九九乘法表已输出到屏幕和文件\"99.txt\"中。");
        } catch (IOException e) {
            System.out.println("写入文件时发生异常：" + e.getMessage());
        }
    }
}