1 Declare a 2D array with double m1020020400 2 Write a metho

1. Declare a 2-D array with

double[][] m={{10,20,0},{20,40,0}};

2. Write a method computeAvg that will take a double 2-D array as the input, compute the average

of 1st and 2nd columns and put the average result at the 3rd column for each row.

3. Write a method printArray to print the values of the 2-D array. The numbers should be aligned.

4. In your main method, call computeAvg first, then call printArray

Solution

public class ArrayAvgCalculation {

   public static void main(String[] args) {
       double[][] m={{10,20,0},{20,40,0}};
       System.out.println(\"Array Before average calculation : \");
       printArray(m);
       m = computeAvg(m);
       System.out.println(\"Array After average calculation : \");
       printArray(m);
   }

   private static double[][] computeAvg(double[][] m) {
       double sum = 0.0;
       double avg = 0.0;
       int i,j;
       for(i = 0; i < m[0].length-1; i++){
           sum = 0.0;
           avg = 0.0;
           for(j = 0; j < m.length; j++){
               sum += m[j][i]; // column wise sum
           }
           avg = sum / j; // sum / number of element in the column
           m[i][(m[0].length)-1] = avg; //m[0].length)-1 ----> for getting last index of column of array \'m\'
       }
       return m;
   }
  
   private static void printArray(double[][] m) {
       for(int i = 0; i < m.length; i++){
           for(int j = 0; j < m[i].length; j++){
               System.out.print(m[i][j]+\" \");
           }
           System.out.println();
          
       }
   }
}