Thread: Multidimensional user defined array question

The program below asks the user for the size of the multidimensional array and creates it. Then, I want to add the total of each rows and display it. I'm having trouble with that. My program adds the total from the previous row and add it to the current total. How can I fix this?

This is what it should look like

How big would you like your matrix?
	Rows - ? 2
	Cols - ? 2
 
Please enter your row 1?
	Column 1 - 1
	Column 2 - 2
 
Please enter your row 2?
	Column 1 - 3
	Column 2 - 4
 
Your total for row 1 is - 3
Your total for row 2 is - 7
 
Your total for the 2 x 2 matrix is 10

This is what it looks like now

How big would you like your matrix?
	Rows - ? 2
	Cols - ? 2
 
Please enter your row 1?
	Column 1 - 1
	Column 2 - 2
 
Please enter your row 2?
	Column 1 - 3
	Column 2 - 4
 
Your total for row 1 is - 3
Your total for row 2 is - 10
 
Your total for the 2 x 2 matrix is 13

import java.util.Scanner;
 
public class ArraySum {
 
    public static void main(String[] args) {
 
        Scanner scan = new Scanner(System.in);
 
        int rows, cols, colValue, rowTotal, matrixTotal;
 
        rowTotal = 0;
        matrixTotal = 0;
 
        System.out.println("How big would you like your matrix?");
        System.out.print("\tRows - ? ");
        rows = scan.nextInt();
        System.out.print("\tCols - ? ");
        cols = scan.nextInt();
 
        System.out.println();
 
        int[][] numberArray = new int[rows][cols];
 
        for(int a=0; a<numberArray.length; a++)
        {
            System.out.println("Please enter your row " + (a+1) + "?");
 
            for(int b=0; b<numberArray[0].length; b++)
            {
                System.out.print("\tColumn " + (b+1) + " - ");
                colValue = scan.nextInt();    
 
                numberArray[a][b] = colValue;
            }
 
            System.out.println();
        }            
 
        for(int c=0; c<numberArray.length; c++)
        {            
            for(int d=0; d<numberArray[0].length; d++)
            {                               
                rowTotal = rowTotal + numberArray[c][d];    
            }   
 
            matrixTotal = matrixTotal + rowTotal;
 
            System.out.println("Your total for row " + (c+1) + " is - " + rowTotal);
        }   
 
        System.out.println();
 
        System.out.println("Your total for the " + rows + " x " + cols + " matrix is " + matrixTotal);
    }
}

It appears that you need to reset rowTotal to zero between trips through the nested for loop.

Originally Posted by GregBrannon

It appears that you need to reset rowTotal to zero between trips through the nested for loop.

Thank you, I didn't think about that, it works now.

You're welcome. Glad to help.