CODEWITHSUNDEEP
perlmultidimensional-array
Aaron
Aaron

Reputation:

How can I print a two-dimensional array in Perl?

I have a two-dimensional array. When I print/dump this I get the following

My two-dimensional array:

push (@matrix, \@a1Comparea2);
push (@matrix, \@a3Comparea4);

a1Comparea2 should be the first row of the array. a3Comparea4 should be the second row of the array.

$VAR1 = [
          [
            '1 6',
            '2 7',
            '3 8',
            '4 9',
            '5 10'
          ],
          $VAR1->[0],
          $VAR1->[0],
          $VAR1->[0],
          $VAR1->[0],
          [
            '7 12',
            '8 13',
            '9 14',
            '10 15',
            '11 16'
          ],
          $VAR1->[5],
          $VAR1->[5],
          $VAR1->[5],
          $VAR1->[5]
        ];

When I try to print this with the following code:

for (my $j= 0; $j < $rows; $j++)
{
    for (my $k= 0; $k < @a1; $k++)
    {
        print "Row:$j Col:$k = $matrix[$j][$k]\n";
    }
}

I get the following output:

Row:0 Col:0 = 1 6
Row:0 Col:1 = 2 7
Row:0 Col:2 = 3 8
Row:0 Col:3 = 4 9
Row:0 Col:4 = 5 10
Row:1 Col:0 = 1 6
Row:1 Col:1 = 2 7
Row:1 Col:2 = 3 8
Row:1 Col:3 = 4 9
Row:1 Col:4 = 5 10

As you can see, the data is duplicated.

Upvotes: 4

Views: 15576

Answers (2)

Curd
Curd

Reputation: 12417

Are you sure you used the code you showed above?

Maybe you used something like:

for (my $j=0; $j < $rows; $j++)
{
    for (my $k=0; $k < @a1; $k++)
    {
        print "Row:$j Col:$k = $matrix[$not_j][$k]\n";
    }
}

$not_j would evaluate always to 0, producing your output.

Upvotes: 1

nik
nik

Reputation: 13450

Is you array correctly defined?
You should use an @ for an array and a $ for a scalar...
Check this article for a quick reference.

That article gives this simple example.

@matrix = (
        [3, 4, 10],
        [2, 7, 12],
        [0, 3, 4],
        [6, 5, 9],
      );

This creates an array with four rows and three columns. To print the elements of the array, type:

for($row = 0; $row < 4; $row++) {
    for($col = 0; $col < 3; $col++) {
        print "$matrix[$row][$col] ";
    }
    print "\n";
}

Upvotes: 3

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