Now, if you have a data file containing lines of data, with perhaps 3 values per line, you might be wanting to load that into a some sort of data structure... perhaps an array of hashes... something like this?

my @SList = qw(Name Latitude Longitude);
my @AoH;

while (<FILE>) {
    chomp;
    my %hash;
    @hash{@SList} = split;   # left-hand-side is called a "hash slice"
    push @AoH, \%hash;
}
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See I know what I mean. Why don't you? to get a feel for what we want to see. Your description is unclear because you use words in an interesting way that doesn't fit with the way we expect. Very likely that all sounds fine in your head, but we haven't the technology to post your head to the site for examination by everyone which makes it hard to answer your question in a way that is likely to help.

As others have suggested, show us your code, but first read the node linked above to help you focus on just what is needed to get the best help from us.

In any case use Data::Dumper (it's core) to inspect the content of @SList

use Data::Dumper; 
print Dumper(\@SList)
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I don't understand the question. The way you use "implemented into" and "extrapolate " is confusing.

So back to Basic debugging checklist

#!/usr/bin/perl --
use strict; use warnings;
use Data::Dump qw/ dd /;
my @foo = qw/ a b c /;
dd( \@foo );
my( $ba, $bar, $rar ) = qw/ q r s /;
dd( $ba, $bar, $rar );
__END__
["a", "b", "c"]
("q", "r", "s")
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Does that help you ask clearer question? Does it answer any questions?

I thought I could initialize scalars which uses the data that qw Latitude / Longitude lists, but I'm having no luck with this. Is it possible?

My guess as to your meaning:

my( $name, $lat, $long ) = qw(Name Latitude Longitude);
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Though it doesn't seem too useful.

Your question is not very clear, but I think what you want is an AoA (array of arrays)

my @list;
push @list, [qw(Name Latitude Longitude)];

#or

my @list = 
    [qw (Name Latitude Longitude)],
    [qw (Name Latitude Longitude)],
    [qw (Name Latitude Longitude)],
    etc ... );
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Is this what you are looking for?

use strict;
use warnings;

sub f {
    print "$_[0]\n";
}

my @SList = qw(Name Latitude Longitude);
foreach my $item (@SList) {
    f( $item );
}
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Unfortunately, you have edited your code TOO much. We really need to see more to understand exactly what you are trying to do. The questions arise because you don't seem to have real values in your @SList array. Those appear to be headers that could be used in a Two Dimensional array or they appear to be keys that could be used in an Array of Hashes. You really need to provide more code and more context.

Additionally, there seems to be some confusion on your end about what qw() is used for -- you question whether or not you should be using scalars instead, without realizing that you already are using scalars. qw() is merely a convenience function that allows us lazy programmers to leave out quotations and commas when creating hard coded arrays, like so:

my @hard2type = ( 'one', 'two', 'three', 'four' );
my @ez2type   = qw( one two three four );
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Finally, perhaps you can elaborate what you mean when you said "... write a foreach loop that will go over each line in the list ..." because as it stands, you have only presented one line, not many. Thanks!

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

qw/STRING/

Evaluates to a list of the words extracted out of STRING, using embedd
+ed whitespace as the word delimiters. It can be understood as being r
+oughly equivalent to:

       split(" ", q/STRING/);

the differences being that it generates a real list at compile time, a
+nd in scalar context it returns the last element in the list. So this
+ expression:

    qw(foo bar baz)
is semantically equivalent to the list:

    "foo", "bar", "baz"
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... a list is an UNordered sequence of values. ... Lists cannot be accessed using an index.

I disagree with both these assertions. To my way of thinking, lists are most certainly ordered. In what sense do you think of them otherwise? They can also be array indexed:

c:\@Work\Perl>perl -wMstrict -le
"my $s = ('foo', 'bar', 'baz')[1];
 print qq{'$s'};
 ;;
 $s = (qw(zip zap zop))[1];
 print qq{'$s'};
 ;;
 $s = qw(hic hac hoc)[1];
 print qq{'$s'};
"
'bar'
'zap'
'hac'
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Note: I think the  qw(hic hac hoc)[1] example relies on a syntactic feature that, if not deprecated, is at least disparaged and contumed, and may be slated to go away someday/someversion (I'm running this with 5.14). It is certainly deprecated (as of 5.14) in a for-loop:

c:\@Work\Perl>perl -wMstrict -le
"for my $s qw(hic hac hoc) {
   print qq{'$s'};
   }
"
Use of qw(...) as parentheses is deprecated at -e line 1.
'hic'
'hac'
'hoc'
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---

Give a man a fish:  <%-(-(-(-<

You are obviously right, thanks to point me in the right direction. I still find difficult to be precise describing Perl behaviour. My attempt was to tell the difference between lists and arrays and the OP confusion undeerstanding the @arr = qw (a b); construct.

Anyway you too are wrong, because the latin demonstrative pronouns are: qw(hic haec hoc) and not qw(hic hac hoc) ...;=)

L*

There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

Suspect one of these examples will get you going:

#!/usr/bin/perl
use strict;


print "-----[ Method 1 ]----------------\n";
my @SList = qw(Name Latitude Longitude);
foreach my $Item_From_SList (@SList)
{
    print "    Item found:  $Item_From_SList\n";
}


print "-----[ Method 2 ]----------------\n";
my ($name, $lat, $long) = qw(Name Latitude Longitude);
print "  Name of Name:  $name\n";
print "   Name of Lat:  $lat\n";
print "  Name of Long:  $long\n";


print "-----[ Method Ends ]-------------\n";

exit;
__END__
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Otherwise, see if you can expand on your question use more but smaller words. In my experience, that's the best way to arrive at a common language.

my @SList = qw(Name Latitude Longitude);
my $FileA = "Mammal.txt";
open my $Mammals, "<", $FileA or die "Cannot open file'$FileA'.";
while (my $line = <$Mammals>) {
    my %data;
    @data{@SList} = split /\t/, $line, scalar @SList;
    foreach my $species (@SList) {
        printf "%-10.10s : %s\n", $species, $data{$species};
    }
}
close $Mammals;
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sub CalculateDistance($$$$)
{
 my ($Lat1, $Lon1, $Lat2, $Lon2) = @_;
 my ($nDLat, $nDLon);
 my ($nA, $nC, $nD);
 
 $nDLat = ($Lat1 - $Lat2) * 0.017453293;
 $nDLon = ($Lon1 - $Lon2) * 0.017453293;
 
 $Lat1 = ($Lat1) * 0.017453293;
 $Lat2 = ($Lat2) * 0.017453293;
 
 $nA = (sin($nDLat/2) ** 2) + cos($Lat1) * cos($Lat2) * ( sin($nDLon/2
+) ** 2 );
 $nC = 2 * atan2( sqrt($nA), sqrt( 1 - $nA )); 
 $nD = 6372.797 * $nC;
 
 return $nD;
}
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    CalculateDistance (54.988056, -1.619444, $Lat2, $Lon2);
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Myotis daubentonii    52.12909504    -0.882318328
Myotis nattereri    53.90074722    -1.771685946
Myotis nattereri    54.08052026    -1.770700447
Myotis nattereri    53.54023273    -1.471802022
Eptesicus serotinus    51.40241395    0.250171498
Eptesicus serotinus    51.35533502    0.242835438
Eptesicus serotinus    51.0001581    0.351815969
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How can you have code that looks like that, and use a phrase like "implement it into the CalculateDistance subroutine"? I guess you have found code somewhere that is doing almost what you want and you wish to bend it to fit? Something like:

    ++$count if CalculateDistance (54.988056, -1.619444, @data{@SList[
+1 .. 2]}) > $x;
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inside your while loop should be the trick.

Perl is the programming world's equivalent of English