File Input / Matrix Lab You are given a file called name_grades.txt with the fol

Question

File Input / Matrix Lab

You are given a file called name_grades.txt with the following text:

John 95 92 85 90

Angela 90 83 82 100

Joe 75 85 68 72

You will store the names in a String array of size three and the grades in a matrix of size four x three. You will then pass the matrix into a method called addThreeMatrix which will add three points to each grade and then return the modified grades. Finally you will pass the name array to a method called modifyName which will change each o to a * and each A (lowercase and uppercase) to a @ and then return the modified array. Finally back in main you will print out the modified names and grades as follows:

J*hn 98 95 88 93

@ngel@ 93 86 85 103

J*e 78 88 71 75

Notes:

Here is an example which changes all letter’s L to a !

String name = “Lenny”;

name = name.toLowerCase();

name = name.replace(“l”,”!”);

This should be completed in java oracle and in one class. Thank you!

Explanation / Answer

public class TestClass {

    public static void main(String args[]) {
       String names[] = {"John", "Angela", "Joe"};
       double grades[][] = {{95, 90, 75}, { 92, 83 , 85}, {85, 82, 68}, {90, 100, 72}};
      
       int m = 3;
       int n = 4;
      
       System.out.println("student data is : ");
       printData(grades, names, m, n);
      
       addThreeMatrix(grades, n, m);
       modifyName(names);
      
       System.out.println("Modified student data is : ");
       printData(grades, names, m, n);
    }
  
  
    public static void printData(double[][] grades, String names[], int m, int n) {
       for (int i=0; i<m; i++) {
           System.out.print(names[i] + " ");
           for (int j=0; j<n; j++) {
               System.out.print(grades[j][i] + " ");  
           }
           System.out.println();
       }
       System.out.println(" ");
    }
  
    public static void addThreeMatrix(double grades[][], int m, int n) {
       for (int i=0; i<m; i++) {
           for (int j=0; j<n; j++) {
               grades[i][j] = grades[i][j] + 3;
           }
       }
    }
  
    public static void modifyName(String names[]) {
       for (int i=0; i<names.length; i++) {
           names[i] = names[i].replace("A", "@");
           names[i] = names[i].replace("a", "@");
           names[i] = names[i].replace('o', '*');
       }
    }
}

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