Perl: grep a value in array in array

Question

How do I grep values from an array of arrays? My attempt:

my $match =grep (/value/, @array);

if ( $match <= 0 ) { ... }

I am always getting zero as a output which is incorrect.

I am able to print $value after 2 for, loops so I think grep will only work when there is 1 loop.

for $value (array) {
    for my $value1 (@$value) 
    { print $value1 };

Thanks.

grep returns a list. If you assign it to a scalar, you will get the length of the list. — Len Jaffe
– Len Jaffe, Commented Jul 7, 2014 at 15:09
That being said, are you saying that you wish to grep vales from a list of lists? — Len Jaffe
– Len Jaffe, Commented Jul 7, 2014 at 15:10
Please ignore Len Jaffe's first comment. grep does not return a list in scalar context (e.g. when assigning its result to a scalar). It would crash the program if it tried. — ikegami
– ikegami, Commented Jul 7, 2014 at 15:14
Please ignore Len Jaffe's second comment. There's no such thing as a list of lists. You were correct when you said array of array. — ikegami
– ikegami, Commented Jul 7, 2014 at 15:16
"Evaluates the BLOCK or EXPR for each element of LIST (locally setting $_ to each element) and returns the list value consisting of those elements for which the expression evaluated to true. In scalar context, returns the number of times the expression was true." How is that substantially different from what I said? — Len Jaffe
– Len Jaffe, Commented Jul 7, 2014 at 15:46

mpapec · Accepted Answer · 2014-07-07 14:52:27Z

1

To grep first level of arrays into @result

my @result = grep { grep { /search/ } @$_ } @array;

grepping final strings into @result,

my @result = grep { /search/ } map { @$_ } @array;

edited Jul 7, 2014 at 14:52

answered Jul 7, 2014 at 14:46

mpapec

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1 Comment

user3457622 Over a year ago

Thanks , so shall I use second level answer as I am looking for answer in 0 or 1 ..Like if I grep something and if value is blank then I shouldn't process. if (@result) { found value } else { array is empty }... I am correct

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