Re: Logical operations on arrays

If the order of the arrays makes no difference, it sounds like you are looking for an intersection operator of some sort. Array::Utils might have what you are looking for. I found this by searching metacpan for "union intersect".

Otherwise, a method to find them is pretty straightforward:

configure a hash for the first array (*)@hash1{@array1} = (1)x@array1
[download]
This configures a hash %hash1 to have a true value for all values found in @array1. (* - This is probably clearer as ~~$hash1{$_} = 1 for @array1~~)
loop through the second array picking out those elements that show up in the first arraypush( @intersection, grep { $hash1{$_} } @array2 );
[download]

There are a couple of assumptions built into the above (@arrayN does not contain an undef value, and the second array only has unique values).

Updates:

Added example code
Added search example
D'oh - quite right Jenda. I have got to stop writing code before my first cup of coffee. :-/

--MidLifeXis

Comment on Re: Logical operations on arrays Select or Download Code

Replies are listed 'Best First'.
Re^2: Logical operations on arrays by Athanasius (Archbishop) on Oct 04, 2012 at 12:24 UTC
See also How do I compute the difference of two arrays? How do I compute the intersection of two arrays?. Athanasius <°(((>< contra mundum	[reply]
Re^2: Logical operations on arrays by Jenda (Abbot) on Oct 04, 2012 at 23:03 UTC
There's no reason to work hard to set the values in the hash to ones, leave them undefined and use exists() within the grep{}. Also there is no reason to push the elements into the @intersection, just assign them. `my %hash1; @hash1{@array1} = (); my @intersection = grep {exists $hash1{$_} } @array2;` [download] Jenda Enoch was right! Enjoy the last years of Rome.	[reply] [d/l]