Exam Grading For this question, you will use multi-dimensional arrays to write a

Question

Exam Grading For this question, you will use multi-dimensional arrays to write a program that grades a multiple choice exam. Your code for this question should go in a file Exam Grading. Java We strongly recommend that you complete the first three warm-up questions before starting this problem. Write a method grade AH Students that takes as input a two dimensional char array containing student responses to a multiple choice exam, and a one dimensional char array containing the solutions to each question. Each element in the 2d array is an array representing one student's responses to the entire exam. This method returns a double [] representing the grades for each student as percentages. Assume that all questions are worth 1 point. You may also assume that all char values are upper-case letters, and valid exam responses. If, at any point, the number of responses for a student does not match the number of questions on the exam (the number of solutions), your method should throw an Illegal Argument Exception that contains a message letting the user know which student (by index) caused the error, as well as what the two conflicting lengths were. Below is an example. Suppose we have a multiple choice exam with 6 questions and written by 4 students: char[][] responses = {{'C', 'A', 'B', 'B', 'C', 'A'}, {'A' 'A', 'B', 'B', 'B' 'B'}, {'C', 'B', 'A', 'B', 'C', 'A'}, {'A', 'B' 'A', 'B', 'B' 'B'}}; char[] solutions = {'C', 'A', 'B', 'B', 'C', 'C'}; The output of grade AH Students would look like: [83.33333333333334, 50.0, 50.0, 16.666666666666664]

Explanation / Answer

Exam.java

import java.util.Arrays;

public class Exam {

   public static void main(String[] args) {
       //Creating an 2-Dimensional char array
       char[][] responses ={{'C','A','B','B','C','A'},
               {'A','A','B','B','B','B'},
               {'C','B','A','B','C','A'},
               {'A','B','A','B','B','B'}};
      
       //Creating one dimensional char array
       char[] solutions={'C','A','B','B','C','C'};
      
       //calling the method by passing the two arrays as arguments
       double[] grades=gradeAllStudents(responses,solutions);
      
       //Displaying the result
       System.out.println(Arrays.toString(grades));

   }

   //This method is used to calculate the score of each student in the each
   private static double[] gradeAllStudents(char[][] responses,
           char[] solutions) {
       int count;
       double grades[]=new double[responses.length];

       for(int i=0;i<responses.length;i++)
       {
           count=0;
           for(int j=0;j<responses[0].length;j++)
           {
               if(responses[i][j]==solutions[j])
               {
                   count++;
               }
           }
           grades[i]=(double)(count*100)/responses[0].length;
      
       }
return grades;
   }

}

______________________

output:

[83.33333333333333, 50.0, 50.0, 16.666666666666668]

_____________________

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