Agfdhyk

I have 2d array (test) and 2d array of number of row needs to be removed (remove Row). The problem is the loop I create resulting in no result when I try to print the test array. I need to create new matrix that not include row 0,1,3,4.

How can I access the new array outside the while loop?

import java.util.ArrayList;

import java.util.Arrays;



public class remove

{

    public static void main( String args )

    {

        double test = { { 100 }, { 200 }, { 300 }, { 400 }, { 500 }, { 600 }, { 700 },

                           { 800 }, { 900 }, { 1000 } };



        int removeRow = { { 0 }, { 1 }, { 3 }, { 4 }, };



        int reduce = 1;

        int r = 0;

        while ( reduce == 0 )

        {

            ArrayList<double> rowsToKeep = new ArrayList<double>( test.length );

            for ( int i = 0; i < test.length; i++ )

            {

                if ( i != removeRow[0][0] - r )

                {

                    double row = test[i];

                    rowsToKeep.add( row );

                }

            }

            r++;

            test = new double[rowsToKeep.size()];

            for ( int i = 0; i < rowsToKeep.size(); i++ )

            {

                test[i] = rowsToKeep.get( i );

            }

            reduce = removeRow.length - r;

            r = r++;

            System.out.println( Arrays.deepToString( test ) );

        }

    }

}

I changed your algorithm a little bit. Here if (j < removeRow.length && removeRow[j][0] == i) we find the row to remove and do nothing just increment j otherwise in else block add the row in rowsToKeep list.

Try this:

double test = { {100}, {200}, {300}, {400}, {500}, {600}, {700}, {800}, {900}, {1000} };

int removeRow = { {0}, {1}, {3}, {4} };

int j = 0;

List<double> rowsToKeep = new ArrayList<>(test.length);

for (int i = 0; i < test.length; i++) {

    if (j < removeRow.length && removeRow[j][0] == i) {

        j++;

    } else {

        double row = test[i];

        rowsToKeep.add(row);

    }

}

test = new double[rowsToKeep.size()];

for (int i = 0; i < rowsToKeep.size(); i++) {

    test[i] = rowsToKeep.get(i);

}

System.out.println(Arrays.deepToString(test));