DO_SOMETHING_WITH-$_

##</code><code>##

#!/usr/bin/perl 

use strict;
use warnings;
use Data::Dumper;


my @array = qw{a b c};
my @new_array = map{my $letter = $_; ++$letter} @array;
print "before: @array\n";
print "after:  @new_array\n";

# with some extra white space
# it looks even more 'inside-out' :-)
my @another = map{
  my_func()
} @new_array;

print "another: @another\n";
print "original \@array: @array\n";



sub my_func {
  my $letter = $_;
  $letter++;
  return $letter;
}

exit;

# DO_SOMETHING_WITH-$_
# doesn't work on a list
for (qw{a b c}){
  # this line generates:
  # "Modification of a read-only value attempted at..."
  ++$_;
}

# so does this
map {++$_} qw{a b c};



##</code><code>##

---------- Capture Output ----------
> "C:\Perl\bin\perl.exe" _new.pl

before: a b c
after:  b c d
another: c d e
original @array: a b c

> Terminated with exit code 0.