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Re^3: Warning is right or not ?

by AnomalousMonk (Monsignor)
on Dec 21, 2012 at 22:07 UTC ( #1009963=note: print w/ replies, xml ) Need Help??


in reply to Re^2: Warning is right or not ?
in thread Warning is right or not ?

... I need the previous value of @data ...

If you mean you need to return the element in the  @data array immediately prior to the first element in the array that matches the string passed into the function, I think I would use something like this (Update: an empty string is returned if no match):

>perl -wMstrict -le "print get_IATA('bar'); ;; sub get_IATA { my ($airline) = @_; ;; my @data = qw(fee fie foe foo barbell boff); ;; for my $i (1 .. $#data) { return $data[$i - 1] if $data[$i] =~ m{ \A \Q$airline\E }xms; } return ''; } " foo

Update: Here's a variation that returns every element in the  @data array immediately prior to an element in the array that matches the string passed into the function. An empty list is returned if no match.

>perl -wMstrict -le "printf qq{'$_' } for get_IATA('bar'); ;; sub get_IATA { my ($airline) = @_; ;; my @data = qw(fee fie yyy barfly foe fum zzz barbell foo); ;; return map { $data[$_] =~ m{ \A \Q$airline\E }xms ? $data[$_ - 1] : () } 1 .. $#data ; } " 'yyy' 'zzz'


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Re^4: Warning is right or not ?
by Anonymous Monk on Dec 23, 2012 at 19:13 UTC

    Thank you very much for your tips. With my irregual data I had to change my code( and data) and your tips helped alot.

    In my check table (csv), I have 3 character codes(ICAO) and their equivalent 2 character codes(IATA) and descriptions. At first, IATA was at first column so I needed previous element of the array when the key was found. But after having an example of irregular ICAO code, which has 2 characters that matches its IATA code, the code didn't help since Perl stops after the first matching. And that IATA code is used three times in the table ( 1 ICAO, 2 IATA)

    Then I changed IATA and ICAO columns' order and changed the code with your help and now it works. Though it may be clumsy, i think its pretty clear.

    --$hash{'AirIATA'}= get_IATA($airlineLoc,$hash{'Airline'}) ; ------------------------------------------------------- sub get_IATA { my $file = shift; my $airline = shift; my @data; open(my $fh, '<', $file) or die "Can't read file '$file' [$!]\ +n"; while (my $line = <$fh>) { my @fields = split(/;/, $line); push @data, @fields; } close($fh); my @results= map { $data[$_] =~ m{ \A \Q$airline\E }xms ? $data[$ +_ + 1] : () } 1 .. $#data; if ($#results>1) { return $results[1]; } elsif ($#results>0) # Do I need a second check, like <2 ? { return $results[0]; } else { print "Airline $airline has no definition in $file fil +e\n"; exit; # Program should stop if there is no match } }

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