Question

我的程序存在一些问题，因为它无法计算每次考试的平均成绩，也无法计算学生的平均成绩和成绩。

有人可以帮助我更正我的代码吗？因为我需要在周三上交作业，还可以帮助我检查那里的其他代码是否有错误。

非常感谢。

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

public class Assignment {

public static void main(String[] args) throws IOException {
    // Variables for input name and output name
    String nameInp = "";
    String nameOut = "";

    // Arrays to store marks of 5 tests of each student
    double [] tests = new double[5];

    // Arrays to store average and sum of the 5 tests
    double[] testAvg = new double[5];
    double[] testSum = new double[5];

    // Arrays to store max and min of the 5 tests
    double[] max = new double[5];
    double[] min = new double[5];

    // Arrays to store the name of students who got max or min
    // in the 5 tests
    String[] nameMax = new String[5];
    String[] nameMin = new String[5];

    // Number of students
    int studCount = 0;

    // Average and grade of the 5 tests of each students
    double studAverage;
    String studGrade;

    // Scanner for reading file
    Scanner scf = new Scanner(new File(System.getProperty("user.dir") +
                              "/src/student_marks.txt"));

    // Set the max and min of the 5 tests
    // to Double's min and max respectively
    double max_tests = Double.MAX_VALUE;
    double min_tests = Double.MIN_VALUE;



    // Print output heading
    System.out.println("Student Name Test1 Test2 Test3 Test4 Test5 Average Grade");
    System.out.println("---------------------------------------------------------");

    // While there are more data to read from the input file
    while (scf.hasNext()) {


      // Increment number of students
        int count;
        count++;

      // Read a student name 
      nameInp = scf.next();

      // Replace the "_" in the name with a " "
      nameOut = nameInp.replaceAll("_", " ");

      // For each student, calculate the sum of the test marks,
      // record the max and min marks of each test and
      tests[5] = scf.nextDouble();
      testSum[5] += tests[5];

      if (tests[5] > max_tests) {
            max_tests = tests[5];
      }
      if (tests[5] < min_tests) {
            min_tests = tests[5];
      }

      // record the name of studunts scoring those max and min marks

      if (tests[5] > max_tests) {
            max_tests = tests[5];
            nameMax[5] = nameOut;
        }
        if (tests[5] < min_tests) {
            min_tests = tests[5];
            nameMin[5] = nameOut;
        }



      // Call the computeStudAvg method to calculate the average marks
      // of each student
        studAverage = computeStudAvg( testAvg );



      // Call the computeStudGrade to get the grade of each student
        studGrade = computeStudGrade(  );


      // Print the tests, average and grade of each student 
      System.out.printf("%-10s %6.2f %6.2f %6.2f\n", nameOut, tests[1], tests[2], tests[3], tests[4], tests[5], studGrade);


    } // end while more students


    // Calculate the average marks of each of the 5 tests
       testAvg[5] = testSum[5] / 5;




    // Print the average of each test
       System.out.printf("Test Average:          ", testAvg[1], testAvg[2], testAvg[3], testAvg[4], testAvg[5]);



    // Print the max marks, min marks and names of students 
    System.out.println("Test      Max--Student                 Min-Student                ");
    System.out.println("------------------------------------------------------------------");
    System.out.printf("Test1" + max[1] , nameMax[1] , min[1] , nameMin[1]);
    System.out.printf("Test2" + max[2] , nameMax[2] , min[2] , nameMin[2]);
    System.out.printf("Test3" + max[3] , nameMax[3] , min[3] , nameMin[3]);
    System.out.printf("Test4" + max[4] , nameMax[4] , min[4] , nameMin[4]);
    System.out.printf("Test5" + max[5] , nameMax[5] , min[5] , nameMin[5]);


    System.out.println();
    scf.close();
  }




// Method to compute and return the average mark of the 5 tests for each student 
  public static double computeStudAvg(double[] testSum) {
    return (testSum[5] / 5 );
  }

  // Method to compute and return the grade of each student
  public static String computeStudGrade(double[] studAvg ) {
      if ( average >=75 ) {
        return "A";
      } else if ( average >= 65 ) {
        return "B";
      } else if ( average >= 50 ) {
        return "C";
      } else if ( average >= 40 ) {
        return "D";
      } else
        return "F"; 
      }
}

Answer 1

您的问题之一是计算最小值和最大值。
反转这些行中的分配：

double max_tests = Double.MAX_VALUE;
double min_tests = Double.MIN_VALUE;

应为：

double max_tests = Double.MIN_VALUE;
double min_tests = Double.MAX_VALUE;

如果您将分数与min_tests进行比较，如果其值为Double.MIN_VALUE，则比较将总是失败，因为没有任何分数低于Double.MIN_VALUE。

计算每项考试的平均分数和学生的成绩

1 个答案: