输出文件没有正确读取输入文件，格式乱序，

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我正在尝试创建一个程序来获取 12 名学生的考试统计数据。在此程序中，输入文件由程序读取，然后打印到输出文件，但存在许多问题。该程序正在读取输入文件但不打印第一个 ID。无论我做什么，C 和 I 都不会打印在 More Right/Wrong 列下。此外，<10 will not print uder the Omit column either.here is my code.

import java.util.Scanner;
import java.io.*;

public class Topic3_HW3 {

    public static void main(String[] args) throws IOException {
        PrintWriter outputFile;
        outputFile = new PrintWriter("HW3_output.txt");
        // outputFile = new PrintWriter(System.out);
        // TODO Auto-generated method stub
        File myFile = new File("C:\\Users\\chroZ\\eclipse-workspace\\Topic3\\src\\Topic3_input.txt");
        Scanner inputFile = new Scanner(myFile);
        // print table header and columns
        outputFile.printf("%40s", "\tTable of Grades");
        outputFile.printf("\n%1s %7s %9s %12s %9s %10s %7s %12s %8s","\nStudent","ID","Correct","Incorrect","Total","More Right/Wrong","Omit","Grade","Percent");
        outputFile.println();
        // declare datatypes for different variables
        double pct;
        int grade, id, corr, incorr, total, omit;
        int student = 0;
        //prompt user to input initial student's ID
        System.out.print("Enter student's ID(negative 1 to stop): ");
        id = inputFile.nextInt();
        while (id != -1) {
            //prompt user to enter said student's wrong/right questions
            System.out.print("\nEnter the amount of questions the student answered correctly: ");
            corr = inputFile.nextInt();
            System.out.print("\nEnter the amount of questions the student answered incorrectly: ");
            incorr = inputFile.nextInt();
            student++;
            total = corr + incorr;
            // print error if total is more than 50 questions
            if (50 < total) {
            System.out.println("ERROR. TOTAL CANNOT EXCEED 50 QUESTIONS. PROCEEDING TO NEXT STUDENT.");}
            System.out.print("\nEnter the desired student's ID(negative 1 to stop): ");
            id = inputFile.nextInt();
            omit = 50 - (corr + incorr);
            grade = corr * 2;
            // calculate percentage correct. type cast correct and total to make sure it
            // doesnt truncate
            pct = (double) corr / total;
            //print if the omitted amount of questions is less, more, or equal to 10
            if (omit < 10)
                outputFile.printf("%-15s", "<10");
            if (10 < omit)
                outputFile.printf("%-15s", "10<");
            if (omit == 10)
                outputFile.printf("%-15s", "10");
            if (corr<incorr)
                outputFile.printf("%-10s","I");
            if(incorr<corr)
                outputFile.printf("%-10s","C");
            if (corr==incorr)
                outputFile.printf("%-10s","=");
            //print values for corresponding columns
            outputFile.printf("\n%1s%14s%7s%12s%12s%9s%11s%10.3f", student, id, corr, incorr, total, omit, grade, pct);
        }
        //notify viewer that program has run
        System.out.println("\nThe program is finished.");
        // flush buffer and close i/o files
        outputFile.flush();
        outputFile.close();
        inputFile.close();
    }
}

]

我尝试更改 Cs 和 Is 的 %-10 格式，但即使我执行 %-100，它仍然不会在百分比列值之前打印。我期待该表打印其相应列的完整值，包括输入文件的第 1 行。我还期待 Cs 和 Is 在更多正确/错误列和 10 下打印

无论我做什么，C 和 I 都不会打印在 More Right/Wrong 列下。

在处理像这样的格式化程序时，列结构在迭代中是相同的非常重要，例如......

outputFile.printf("\n%1s %7s %9s %12s %9s %10s %7s %12s %8s","\nStudent","ID","Correct","Incorrect","Total","More Right/Wrong","Omit","Grade","Percent");
//...
outputFile.printf("\n%1s%14s%7s%12s%12s%9s%11s%10.3f", student, id, corr, incorr, total, omit, grade, pct);

第一个标题列是1个字符宽，第二个是7，但是第二个输出列是14??

现在，考虑到 

Student
无论如何都是 7 个字符宽，第一列的宽度没有意义。

相反，它“应该”看起来更像……

System.out.printf("\n%-7s %-4s %-7s %-9s %-5s %-16s %-4s %-6s %-8s", "Student", "ID", "Correct", "Incorrect", "Total", "More Right/Wrong", "Omit", "Grade", "Percent");
//...
System.out.printf("\n%7d %4d %7d %9s %5s %16s %4d %6.3f %3.2f", student, id, corr, incorr, total, value, omit, grade, pct);

此外，<10 will not print uder the Omit column either.here is my code.

是的，这是因为您在打印任何其他信息之前打印了“省略”。虽然你“可以”这样做，但从可读性的角度来看，你应该在打印时将“省略”信息作为整个数据的一部分包括在内。

所以，我稍微修改了您的代码以修复列并将“省略”信息添加到最终数据行中...

File myFile = new File("marks.txt");
try (Scanner inputFile = new Scanner(myFile)) {
    // print table header and columns
    System.out.printf("%40s", "\tTable of Grades");
    System.out.printf("\n%7s %4s %7s %10s %9s %16s %4s %5s %8s", "Student", "ID", "Correct", "Incorrect", "Total", "More Right/Wrong", "Omit", "Grade", "Percent");
    System.out.println();

    int student = 0;

    int id = inputFile.nextInt();
    while (id != -1) {
        int corr = inputFile.nextInt();
        int incorr = inputFile.nextInt();
        student++;
        int total = corr + incorr;
        // Not sure if this has anything to do with your current
        // assignment, but it's just adding noise
        //if (50 < total) {
        //    System.out.println("ERROR. TOTAL CANNOT EXCEED 50 QUESTIONS. PROCEEDING TO NEXT STUDENT.");
        //}
        int omit = 50 - (corr + incorr);
        double grade = corr * 2;
        // calculate percentage correct. type cast correct and total to make sure it
        // doesnt truncate
        double pct = (double) corr / total;
        //print if the omitted amount of questions is less, more, or equal to 10
        String value = "";
        if (omit < 10) {
            value = "<10";
        }
        if (10 < omit) {
            value = "10<";
        }
        if (omit == 10) {
            value = "10";
        }
        if (corr < incorr) {
            value = "I";
        }
        if (incorr < corr) {
            value = "C";
        }
        if (corr == incorr) {
            value = "=";
        }
        //print values for corresponding columns
      //System.out.printf("\n%7s %4s %7s %10s %9s %16s %4s %5s %8s", "Student", "ID", "Correct", "Incorrect", "Total", "More Right/Wrong", "Omit", "Grade", "Percent");
        System.out.printf("\n%7d %4d %7d %10s %9s %16s %4d %5.3f %3.2f", student, id, corr, incorr, total, value, omit, grade, pct);

        id = inputFile.nextInt();
    }
    //notify viewer that program has run
    System.out.println("\nThe program is finished.");
    // flush buffer and close i/o files
}

现在打印

                            Table of Grades
Student ID   Correct Incorrect Total More Right/Wrong Omit Grade  Percent 

      1 1234      10        11    21                I   29 20.000 0.48
      2 1002      47         2    49                C    1 94.000 0.96
      3 9000      31        19    50                C    0 62.000 0.62
      4 8110      12        10    22                C   28 24.000 0.55
      5 9062      40         0    40                C   10 80.000 1.00
      6 9001      25        25    50                =    0 50.000 0.50
      7 2764       1        49    50                I    0  2.000 0.02
      8 1010      10        10    20                =   30 20.000 0.50
      9 2324      19        30    49                I    1 38.000 0.39
     10 1623      20        28    48                I    2 40.000 0.42
     11 1423      20        30    50                I    0 40.000 0.40
     12 6969       0        50    50                I    0  0.000 0.00
     13 4200      41         6    47                C    3 82.000 0.87
The program is finished.

现在，如果您希望列右对齐，那么您可以在列宽前使用

-
，例如
%-7d

java file-io printf
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