# I want to know how to calculate and display the sum of each column in 2D array

• 03-03-2011, 07:02 AM
Javanoobs
I want to know how to calculate and display the sum of each column in 2D array
I want tp create method that calculate and display the sum of each column of a 2D array, for example :

2 6 -1 5
8 2 7 -5
1 0 4 4

The method should display as follow :

The sum of column 0 is 11
The sum of column 1 is 8
The sum of column 2 is 10
The sum of column 3 is 4

I have declared the array in the main program:
Code:

```public class Main { static final int MAXROW;    <-----  MAXROW is a global int constant static final int MAXCOL;    <-----  MAXCOL is a global int constant               public static void main(String[] args) {                 float[][]A = new float[MAXROW][MAXCOL];                                          }```
and have some method :
Code:

```private void calculateColumn(int[][] array, int j) {     int sum= 0;     for (int row= 0; row < a.length; a++)     sum+= a[row][j];     System.out.println("The sum of column" +j+ "is" + sum); } public void calculate(int[][] array) {   for (int col= 0; col < array[0].length; col++)         calculateColumn(array, col);   }```
im stuck in main part because I not very sure whether the method i created is working fine, somomore i not clear how to call the method in the main part
I know the code seesm defect but this is all i got so far,sorry for the limitation of my knowledge...
any suggestion and correction are welcome
• 03-03-2011, 07:43 AM
subith86
Quote:

Originally Posted by Javanoobs
somomore i not clear how to call the method in the main part

If you don't know how to call a method I'd suggest you learn some basics before you start.

You methods too, are almost wrong.

Code:

```for (int row= 0; row < a.length; a++)         sum+= a[row][j];```
Instead of "j" and "a" it should be "row". Think about the logic.
This will calculate the sum of zero-th column. Now you think about a way how to calculate the sum of 1st and 2nd columns.

You need to learn about arrays also before proceeding