How to check whether an element is present in an array of array

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

Hello, I am having an array of array consisting of three elements

@arr1=(1,2,3,4,5);
@arr2=(6,7,8,9,10);
@arr3=(11,12,13,14,15);
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@mainarr contains all the three arrrays. How can i check whether an element is present in the mainarr? For single arrays we can use like


grep(/tofind/i,@arr)
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.... can anyone suggest something similar to that??????

Comment on How to check whether an element is present in an array of array Select or Download Code

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Re: How to check whether an element is present in an array of array by kilinrax (Deacon) on Jun 05, 2009 at 10:59 UTC
Well, if you have something like: `my @arr1 = (1,2,3,4,5); my @arr2 = (6,7,8,9,10); my @arr3 = (11,12,13,14,15); my @mainarr = (\@arr1, \@arr2, \@arr3);` [download] Or more simply: `my @mainarr = ([1,2,3,4,5], [6,7,8,9,10], [11,12,13,14,15]);` [download] Then you can check for the existence of an element in each subarray just by deferencing with map: `grep { $_ == $tofind } map { @$_ } @mainarray;` [download] (note the use of '==' instead of a regex to match numbers) However, that isn't terribly efficient, depending on the nature of the data you're actually searching. Some more context would be helpful here.	[reply] [d/l] [select]
Re: How to check whether an element is present in an array of array by dpetrov (Acolyte) on Jun 05, 2009 at 11:24 UTC
May be I am wrong, but... if @mainarr is array of array... `@arr1=(1,2,3,4,5); @arr2=(6,7,8,9,10); @arr3=(11,12,13,14,15); my @mainarr = ( \@arr1, \@arr2, \@arr3 );` [download] ... you probably could do: `my %index = map { map { $_ => 1 } @$_ } @mainarr; print "found" if $index{ 'tofind' };` [download]	[reply] [d/l] [select]
Re: How to check whether an element is present in an array of array by irah (Pilgrim) on Jun 05, 2009 at 10:44 UTC
The direct answer available in perldoc. `@mainarr = (1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15); @is_tiny_prime = (); for (@primes) { $is_tiny_prime[$_] = 1 } # or @istiny_prime[@primes] = (1) x @primes;` [download] Now you check whether `$is_tiny_prime[$some_number].` If the number available in array, it print 1, else 0.	[reply] [d/l] [select]
Re: How to check whether an element is present in an array of array by bichonfrise74 (Vicar) on Jun 05, 2009 at 15:44 UTC
It looks like your post is very similar to this node Array of array . Have you check this yet?	[reply]
Re: How to check whether an element is present in an array of array by Anonymous Monk on Jun 05, 2009 at 10:40 UTC
You do not have an array of arrays ree.	[reply]


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