CODEWITHSUNDEEP
javaarraysmultidimensional-array
Chewy
Chewy

Reputation: 85

Finding index & column in a two dimensional array with the most amount of 1's

Writing a program where I randomly insert 0's and 1's into a 4 x 4 array matrix and then need to return the column and row index where 1's occur the most. My first method which checks the rows works fine, but I am having issues in my second check column method.

The error is saying that it cannot find the symbol for variable "col". 

public class AssignmentEight_MultiArray {
 public static void main(String[] args) {

 System.out.println("Beginning to insert random integers into array..");

 // Declare array matrix
 int[][] matrix = new int[4][4];

 // For loop to insert integers into the array 
 for (int row = 0; row < matrix.length; row++) {
  for (int col = 0; col < matrix[row].length; col++) { 
  int ranNum = (Math.random() < 0.5) ? 0:1;
  matrix[row][col] = ranNum;
  }
 }

// Display contents of the array
System.out.println("The values of the array are printed below");

showArray(matrix);

System.out.println();

System.out.print("The largest row index: " + scanRow(matrix) + "\n");
System.out.print("The largst column index: " + scanColumn(matrix) + "\n");


} // end main

// method to show array contents 
private static void showArray(int[][] array) {
 for (int row = 0; row < array.length; row++) {
   for (int col = 0; col < array[row].length; col++)
     System.out.print(array[row][col] + "\t");
   System.out.println();
 }
}

// row index method 
private static int scanRow(int[][] array) {
 int result = -1;
 int highest = -1;

for (int row = 0; row < array.length; row++) {
 int temp = 0;
 for (int col = 0; col < array[row].length; col++) {
 // assign current location to temp variable
 temp = temp + array[row][col];
 }

if (temp > highest) {
  highest = temp;
  result = row;
}

}
return result;
} // end of row method

// column index method
private static int scanColumn(int[][] array) {
 int result = -1;
 int highest = -1;

for (int row = 0; row < array.length; row++) {
int temp = 0;  
for (int col = 0; col < array[row].length; col++) {
// assing current location to temp variable
temp = temp + array[row][col];
}

if (temp > highest) {
 highest = temp;
 result = col;
}

}
 return result;
} // end column method  


} // end class

Upvotes: 2

Views: 2667

Answers (2)

TioDavid
TioDavid

Reputation: 36

I think, for a good way, you should use the variable col like this:

        private static int scanColumn(int[][] array) {
         int result = -1;
         int highest = -1;
// declare and initialize the variable(here you've 'created' it, to then call it on if statement)
         int col = 0;

        for (int row = 0; row < array.length; row++) {
            int temp = 0;
        //declare the variable in the for loop
            for (col = 0; col < array[row].length; col++) {
                // assing current location to temp variable
                temp = temp + array[row][col];
            }

            if (temp > highest) {
             highest = temp;
            result = col;
            }

        }
         return result;
        }

Upvotes: 0

Jo&#227;o Costa
Jo&#227;o Costa

Reputation: 412

I think you are talking about the error caused by this piece of code: 

            for (int col = 0; col < array[row].length; col++) {
// assing current location to temp variable
                temp = temp + array[row][col];
            }

            if (temp > highest) {
                highest = temp;
                result = col;
            }

if you notice the braces closes before the your result = col;
col doesn't exist outside of the for loop.

Upvotes: 2

Related Questions