From which it can be seen that there is some virtue in using modules, especially when they are core! Code is:

• generally clearer
• easier to maintain
• more likely to work first time
• shorter
• easier to write tests for

And modules generally have decent documentation with examples and save rewriting wheels badly.

with examples and save rewriting wheels badly.

Ah, the old subliminal hint ;) haha. I def understand what you mean though, I was just giving an example :)

As long as experimental feature warnings are not a concern.

Here's a similar way, but instead of using the experimental switch, I use a dispatch table. Note this destroys @ARGV in the process and definitely is only an example and shouldn't be used in production code without much more work.

use warnings;
use strict;

my ($file, $thing);

my %arg_table = (
    -f      => sub { $file = shift; },
    -t      => sub { $thing = shift; },
    default => sub { die "bad param"; }, 
);

while (my @args = splice @ARGV, 0, 2){
    if (defined $arg_table{$args[0]}){
        $arg_table{$args[0]}->($args[1]);
    }
    else {
        $arg_table{default}->();
    }
}

print $file if defined $file;
print $thing if defined $thing;
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use strict;
use warnings;

my @ARGV = qw(-infile data_in.bin -outfile data_out.bin);

my %args;

for ( 0 .. $#ARGV / 2 ) {
    my $switch = shift(@ARGV);
    my $value  = shift(@ARGV);
    $args{$switch} = $value;
}

print "Infile: $args{-infile}\n", "Outfile: $args{-outfile}" if ( exis
+ts $args{-infile} && exists $args{-outfile} );
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my %hash = { key => [value_1, value_2, value_3, value_4]};
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There appears to be no benefit to your use of a for loop in that code. Standard hash population means that it isn't needed.

use strict;
use warnings;

my @ARGV = qw(-infile data_in.bin -outfile data_out.bin);

my %args = @ARGV;

print "Infile: $args{-infile}\n", "Outfile: $args{-outfile}" if ( exis
+ts $args{-infile} && exists $args{-outfile} );
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works just the same. HTH.

PS. I wouldn't use @ARGV for a lexical variable name since it ordinarily has a special meaning.

I tested it and it does indeed work. How is this possible? How does it know to put the filenames into their respective places? Does it somehow auto assign a key/value pair? Im just as confused lol, because I thought you had to shift the array to get the next value, but somehow it automatically did it :0 This is what i did:

use strict;
use warnings;

my %args = @ARGV;

print "Infile: $args{-infile}\n", "Outfile: $args{-outfile}" if ( exis
+ts $args{-infile} && exists $args{-outfile} );
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I fed it '-infile data_in.bin -outfile data_out.bin'. and it almost seems like it has assigned key/value pairs based off of my thought patterns lol <.<

I guess what i am asking is, how did it build the hash? and why did my %args = @ARGV; build it correctly like that. How is 'data_in.bin' and 'data_out.bin' not a key? if key -infile contains value 'data_in.bin' then what assigned 'data_in.bin' to be its value? there was no shifting or anything to loop through the input args