java - 如何获得将二维数组打印到java中的两个文件中的函数？

Question

我的目标是获取一个包含名称和数字的文件，第一行将命名列，后面的行将是数据。第 0 列将包含名字，第 1 列将包含姓氏，这两个列将被合并。第 2、3 和 4 列将包含将一起平均的 3 个数字，第 5 至 11 列也将包含将一起平均的数字。这将是测试数据:

first, last, #1, #2, #3, #4, #5, #6, #7, #8, #9, #10
Dan, Smith, 56, 58, 55, 66, 44, 78, 60.33, 52.33, 70.66, 44
Sam, Will, 77, 88, 55, 99, 77, 10, 62, 65, 59, 62

从这里开始，两个输出文件将包含相同的信息，第二个输出文件将以更整齐的方式排列信息。我想要的输出是:

name, exam score,hw score,min score
Dan Smith, 56.33, 62.66, 56.33
Sam Will, 73.33, 62, 62

此行将仅用于第二个输出文件:

out.printf("%20s: %10.2f, %8.2f, %9.2f\r\n",name, average1, average2, smallestaverage);

我的代码如下，我尝试测试并查看是否可以使用 for 循环打印出部分数据，但只会收到为两个变量设置的原始值:

import java.util.Scanner;
import java.util.ArrayList;
import java.io.File;
import java.io.PrintWriter;
public class compute_grades {
    public static void process_grades(String input_name, String csv_name, String pretty_name) {
        String[][] data = read_spreadsheet(input_name);
        String csvname = "csv_name.txt";
        String pretty = "pretty_name.txt";
        PrintWriter out = null;
        try {
            out = new PrintWriter(input_name);
        } catch (Exception e) {
            System.out.printf("Error: failed to open file %s.\n", input_name);
            System.exit(0);
        }
        String first = "dog";
        String last = "dat";
        for (int i = 0; i < data.length; i++) {
            first = data[i][0];
            last = data[i][1];
        }
        System.out.println(first + last);
    }
    public static String[][] read_spreadsheet(String filename) {
        ArrayList < String > lines = read_file(filename);
        if (lines == null) {
            return null;
        }
        int rows = lines.size();
        String[][] result = new String[rows][];
        for (int i = 0; i < rows; i++) {
            String line = lines.get(i);
            String[] values = line.split(",");
            result[i] = values;
        }
        return result;
    }
    public static ArrayList < String > read_file(String filename) {
        File temp = new File(filename);
        Scanner input_file;
        ArrayList < String > result = new ArrayList < String > ();
        try {
            input_file = new Scanner(temp);
        } catch (Exception e) {
            System.out.printf("Failed to open file %s\n", filename);
            return result;
        }
        while (input_file.hasNextLine()) {
            String line = input_file.nextLine();
            result.add(line);
        }
        input_file.close();
        return result;
    }
    public static void main(String[] args) {
        Scanner in = new Scanner(System. in );
        System.out.printf("Please enter the name of the input file: ");
        String input_name = in .next();
        System.out.printf("Please enter the name of the output CSV file: ");
        String csv_name = in .next();
        System.out.printf("Please enter the name of the output pretty-print file: ");
        String pretty_name = in .next();
        process_grades(input_name, csv_name, pretty_name);
        System.out.printf("\n\nExiting...\n");
    }
}

Answer 1

我不明白你的两个输出文件之间的区别，但我认为你的处理方法应该如下所示:

public static void process_grades(String input_name, String csv_name, String pretty_name) {
    String[][] data = read_spreadsheet(input_name);

    PrintWriter out = null;
    try {
        out = new PrintWriter(csv_name);
    } catch (Exception e) {
        System.out.printf("Error: failed to open file %s.\n", input_name);
        System.exit(0);
    }
    // print header
    out.printf("name, exam score,hw score,min score\r\n");
    // go throu all the other rows
    for (int row = 1; row < data.length; row++) {
        // get Name
        String name = data[row][0] + " "+ data[row][1];
        // avg the next three cols
        double average1 = 0;
        for(int col = 2; col < 5; col++)
            average1 += Double.parseDouble(data[row][col].trim());
        average1 /= 3;
        // avg the next seven cols
        double average2 = 0;
        for(int col = 5; col < 12; col++)
            average2 += Double.parseDouble(data[row][col].trim());
        average2 /= 7;
        //get min score
        double smallestaverage = Math.min(average1,average2);
        // print the content
        out.printf("%20s: %10.2f, %8.2f, %9.2f\r\n",name, average1, average2, smallestaverage);
    }
    // flush the output and close the writer
    out.flush();
    out.close();
}