Length of multidimensional array based on the particular index value

k_manimuthu has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks,

Currently I am trying to get the length of the multidimensional array based on some index position. The values are Boolean. I want to count the index (x,2) value equals to ‘1’.

I got the answer for the below code. Please suggest any other smart way to get this?

Thanks

@select = (
['AAA','A Description',1,0],
['BBB','B Description',0,0],
['CCC','C Description',0,0],
['DDD','D Description',1,0],
['EEE','E Description',1,0],
);

for (my $i=0; $i<@select; $i++)
{
    $length++ if($select[$i][2]);
}

print "\nSelective Length : ", $length; 
=output
3
=cut
[download]

Comment on Length of multidimensional array based on the particular index value Download Code

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Re: Length of multidimensional array based on the particular index value by davido (Cardinal) on Feb 24, 2011 at 10:07 UTC
grep in scalar context... evil? It works. `say scalar grep{ $_->[2] } @select;` [download] There's also 'for' `my $length; $length++ if $_->[2] for @select; say $length;` [download] Dave	[reply] [d/l] [select]
Re^2: Length of multidimensional array based on the particular index value by Eliya (Vicar) on Feb 24, 2011 at 10:23 UTC
`$length++ if $_->[2] for @select;` Unfortunately, Perl doesn't understand this "double modifier" syntax (`syntax error at..., near "] for "`), so it would have to be: `do { $length++ if $_->[2] } for @select;` [download]	[reply] [d/l] [select]
Re^3: Length of multidimensional array based on the particular index value by BrowserUk (Patriarch) on Feb 24, 2011 at 10:33 UTC
it would have to be: `do { $length++ if $_->[2] } for @select;` Can also be: `$_->[2] and $length++ for @select;` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]
Re^4: Length of multidimensional array based on the particular index value by jwkrahn (Abbot) on Feb 24, 2011 at 10:48 UTC
Re^3: Length of multidimensional array based on the particular index value by davido (Cardinal) on Feb 24, 2011 at 10:34 UTC
there you go taking all my fun away! Here's an awful contortion: `$_->[2]?length++:0 for @select;` [download] Dave	[reply] [d/l]
Re^4: Length of multidimensional array based on the particular index value by jwkrahn (Abbot) on Feb 24, 2011 at 10:40 UTC
Re^4: Length of multidimensional array based on the particular index value by Eliya (Vicar) on Feb 24, 2011 at 10:43 UTC
Re: Length of multidimensional array based on the particular index value by jwkrahn (Abbot) on Feb 24, 2011 at 10:15 UTC
`$ perl -le' my @select = ( [ "AAA", "A Description", 1, 0 ], [ "BBB", "B Description", 0, 0 ], [ "CCC", "C Description", 0, 0 ], [ "DDD", "D Description", 1, 0 ], [ "EEE", "E Description", 1, 0 ], ); my $length = grep $select[ $_ ][ 2 ], 0 .. $#select; print "Selective Length : $length"; ' Selective Length : 3` [download]	[reply] [d/l]
Re: Length of multidimensional array based on the particular index value by k_manimuthu (Monk) on Feb 24, 2011 at 10:50 UTC
Hi all, Thanks a lot for your valuable suggestion. Here I learned some new things. Thanks	[reply]