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Re^2: popping, shifting or splicing an array???

by drock (Beadle)
on Aug 10, 2005 at 21:00 UTC ( #482761=note: print w/replies, xml ) Need Help??

in reply to Re: popping, shifting or splicing an array???
in thread popping, shifting or splicing an array???

Joel, I have to disagree. An array of hashes is really not necessary b/c I do not need to lookup or reference any element by name. What is in the elements is H02043-H02999 for example. All I need is once the user selection is stored in my tape_import array I need to splice these selections out of the main array and present an updated main array or a whole new array. Here is my code thus far:
sub import99 { print $q->h3 ({-style=>'Color:#0000CC'},'Please Choose 9940 Tape Ran +ge for Import.'), $q->h3 ({-style=>'Color:#CC3300'},'Note: Inject Tapes via Acsls Prior +To Import!'); my @H99tapes =('H02043' .. 'H02999'); ##--##MAINARRAY my @UserH99tapes = @H99tapes;##--## USER SELECTIONS print $q->scrolling_list('htapes99',[@H99tapes],[$H99tapes[0]],10,-mul +tiple=>'true',my %attributes), $q->submit('form','Submit'), $q->reset; ##--BEGINIMPORT ##--## AS H NUMBERS ARE SELECTED, REMOVE SUBMITTED ELEMENTS ##--## FRO +M USER ARRAY ##--## REPOPULATE LIST INTO NEW ARRAY,PRINT NEW ARRAY my @tape_imports = $q->param(htapes99); ##--## SELECTED BY USER my $tape_count = scalar @tape_imports; $[=0; foreach (@tape_imports) { splice (@H99tapes,0,$tape_count,@H99tapes) } } ##--## END ROUTINE import99 ##--##

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Re^3: popping, shifting or splicing an array???
by injunjoel (Priest) on Aug 11, 2005 at 20:00 UTC
    Greetings again,
    Okay so maybe the hash in not in order but I have a few questions about your current approach.
    Since you are allowing for multiple selections in your scrolling_list
    print $q->scrolling_list('htapes99',[@H99tapes],[$H99tapes[0]],10,-mul +tiple=>'true',my %attributes);
    if the user selected four elements from random places in the list then the first five values are clipped from the list, four times. Not the elements the user selected.
    my $tape_count = scalar @tape_imports; foreach (@tape_imports) { splice (@H99tapes,0,$tape_count,@H99tapes) }
    It seems like each time through your foreach (hypothetically four times) you clip the the elements in @H99tapes from 0 to $tape_count (in this case 4) so five elements are removed from the beginning of the array. Also by replacing the missing values with the entire list again you are increasing the size of your list almost exponentially, at least by a factor of scalar(@H99tapes) - (scalar(@tape_imports) + 1). In a test I ran with your code and four random values the resulting size of @H99tapes was 15252! Its starting size was 957.
    The impetus behind my hash suggestion was that you could use the map to remove those elements with the same value as those the user selected rather than trying to manipulate the list based on positional index, however looking at your code a hash is not in order, yet the logic still is. So it seems like you would want to remove those values stored in @tape_imports from the @H99tapes list. In that case you could use the first example from my previous post.
    my @H99tapes =('H02043' .. 'H02999'); #...form stuff here my @tape_imports = $q->param(htapes99); #clean out all the values in @tape_imports from @H99tapes @H99tapes = do{ my @a = @H99tapes; #make a local copy of our list #now @a gets fed element by element into our map block #and its value is assigned to $_ map { #local copy of incoming value for map. We do this #because grep also assigns its values to $_ so #in order to not confuse things we assign it to a #locally scoped var $v my $v = $_; #check if this value is in the forbidden #list @tape_imports or not. We anchor the #regexp to avoid partial matches from other #values like '90' matching against '1905'. (!grep /^$v$/, @tape_imports) ? $v : (); } @a; };
    Does that makes sense? Or am I not getting it? I think splice might not be what you are looking for since it deals with postional indexing rather than element values. You would need to know what postions in your @H99tapes array the user selected elements are at in order to accurately splice them out. Since map returns a list we can just re-write the @H99tapes array with a grep call to filter out unwanted values, regardless of position.

    "I do not feel obliged to believe that the same God who endowed us with sense, reason and intellect has intended us to forego their use." -Galileo

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