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How Do I Compare Array A to Array B, removing B elements from A.

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Contributed by fuzzball on Mar 21, 2002 at 19:50 UTC
Q&A  > arrays


Description:

I need to take a array of URL's in @A, compare it to a array of "banned" domain names in @B, and either remove matches from @A, or put non-matches into a new array, @C. Given example data:
@A = ( 'yahoo.com', 'altavista.com', 'yahoo.com/index.html' ); @B = ( 'yahoo.com', 'webcrawler.com' );
@A (or @C) should end up with only 'altavista.com'. Clearly, it is has to match with patterns, not just exact string equality.

Answer: How Do I Compare Array A to Array B, removing B elements from A.
contributed by merlyn

my @C; OUTER: for ( @A ) { for my $pat ( @B ) { if ( /\Q$pat/i ) { next OUTER; } } push @C, $_; }
Answer: How Do I Compare Array A to Array B, removing B elements from A.
contributed by dragonchild

Something like:

my @C = grep { my $x = $_; not grep { $x =~ /\Q$_/i } @B } @A;

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