I am trying to find the average of rows i have on a jagged 2d array I already printed the array out but the average part is printing out the wrong averages. what is wrong with my code?

//print array
        for(int k = 0; k < arr.length; k  { 
            for(int j = 0; j < arr[k].length; j  ) {

             System.out.print(arr[k][j]   " ");             
            }

            System.out.println();
        }
      
 //average

        for (int r = 0; r < arr.length; r  ){
            double sum = 0.0;
            double avg = 0.0;
            for (int c = 0; c < arr[r].length; c  ){
                sum  = arr[r][c];  
                avg = sum / i; // i is the columns of the array;


            }
           
           
        System.out.println("Row "   (row   1)   " average is: "   avg);
            

        }

CodePudding user response：

Rather than working out the average on the fly you should calculate it at the end only by moving avg = sum / i; outside of the nested loop otherwise it will divide by an incorrect every time it loops. Also use avg = sum / arr[r].length; instead because we know exactly how many columns each row has:

    for (int r = 0; r < arr.length; r  ){
        double sum = 0.0;
        for (int c = 0; c < arr[r].length; c  ){
            sum  = arr[r][c];  
        }
        //Calculate the average outside the nested loop using (sum / columns)
        double avg = avg = sum / arr[r].length;
        System.out.println("Row "   (row   1)   " average is: "   avg);
    }