Re: Is there a cleaner way to write this code below, which includes derferencing references, that themselves have to be dereferenced?

OK a few observations:

    ### grabbing every column
    my $dbCommand = qq^select ^;
    foreach (@ticketsFields) {
        $dbCommand .= "$_,";
    }
    $dbCommand =~ s/,$//;
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ok I think all of that is simply:

my $dbCommand = 'select '.join ',',@ticketsFields;
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Why do you need this copy? and deref doesn't need {} , just use @$rows ..

my @newArray = @{$rows};
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All of this:

 for(my $x = 0; $x < $ticketsFieldsSize; $x++)
            {
                ### assign the key and value in the hash
                $GenericData{$ticketsFields[$x]} = $newArray[$x];
            }
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might be something like:

@GenericData{@ticketsFields} = @$rows;
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and lastly, you don't need a "return" at the end- whatever value is at the end, IS returned:

\@ticketsRecords;
}
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Re^2: Is there a cleaner way to write this code below, which includes derferencing references, that themselves have to be dereferenced? by bartender1382 (Beadle) on May 05, 2022 at 19:57 UTC
Thank you for this: `@GenericData{@ticketsFields} = @$rows;` It works great, just would like to understand it. Why isn't it? %GenericData{@ticketsFields} = @$rows; Since I am building a hash, I would have just assumed the above. Just want to understand why it's being called as an array instead of a hash. Thanks again	[reply] [d/l]
Re^3: Is there a cleaner way to write this code below, which includes derferencing references, that themselves have to be dereferenced? by GrandFather (Saint) on May 05, 2022 at 21:58 UTC
`$, % and @` are sigils. They denote the type of thing being returned from an expression. They are not the type of a variable. So `$rows` is a variable ('rows') returning a scalar value. `@$rows` is a scalar variable deferenced to return an array. You can index into a hash variable (`%GenericData` for example) to get a scalar value - the value associated with the key that was used: `my $value = $GenericData{key};`. 'GenericData' in that case is the hash variable, but the indexing expression returns a scalar value. Perl also lets you slice hashes and arrays. In that case an array of values is returned so regardless of it being an array slice or a hash slice `@` is used to show an array being returned: `my @values = @GenericData{@ticketsFields}`. An interesting and useful wrinkle is that you can then assign an array to the slice. Consider the following example which reverses the order of values associated with keys in a hash using assignment between hash slices: `use strict; use warnings; my %hash = (one => 1, two => 2, three => 3); my @keys = sort {$hash{$a} <=> $hash{$b}} keys %hash; print "$_ => $hash{$_} " for @keys; print "\n"; @hash{@keys} = @hash{reverse @keys}; print "$_ => $hash{$_} " for @keys;` [download] Prints: `one => 1 two => 2 three => 3 one => 3 two => 2 three => 1` [download] Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply] [d/l] [select]