Further question on removing elements from arrays

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

Hi guys,

I was taught this

my (%a, %b);
@a{@a} = ();
@b{@b} = ();
delete @a{@b};
delete @b{@a};
@a = keys %a;
@b = keys %b;
[download]

to get same elements out but if I want to retain the same elements and remove the different ones, is there a simple method like this?

Thanks.

Desmond

Comment on Further question on removing elements from arrays Download Code

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Re: Further question on removing elements from arrays by Zaxo (Archbishop) on Aug 25, 2005 at 05:41 UTC
You can use grep. `my (%a, %b); @a{@a} = (); @b{@b} = (); @a = grep {exists $b{$_}} @a; @b = grep {exists $a{$_}} @b;` [download] Now @a and @b should be equal, containing only the common elements. Added - fixed missing curlies, tlm++. After Compline, Zaxo	[reply] [d/l]
Re: Further question on removing elements from arrays by davidrw (Prior) on Aug 25, 2005 at 11:43 UTC
Also check out (which includes Zaxo's method for the intersection, as well as methods for the union and difference): Categorized Questions and Answers QandASection: arrays How can I find the union/difference/intersection of two arrays?	[reply]