my @array = qw(red blue green yellow black white purple brown orange gray);
foreach (@array) {
    do_something_with($_);
}

##</code><code>##

#  Inputs:  $1 ... color name
#           $2 ... The color index (a new arg)
##
sub do_something_with {
    my ($color, $idx) = @_;
    # For now, just print the color prefixed with its index...
    printf " %2d.  '$color'\n", $idx;
}

##</code><code>##

for (my $i = 0; $i < @array; $i++) {
    my $item  = $array[$i];
    do_something_with($item, $i);
}

##</code><code>##

my $i;
foreach (@array) {
    do_something_with($item, $i++);
}

##</code><code>##

use feature ":5.10";
my @array = qw(red blue green yellow black white purple brown orange gray);
foreach (@array) {
    do_something_with($item, state i++);
}

# Prints
#  0.  'red'
#  1.  'blue'
#  2.  'green'
#  3.  'yellow'
#  4.  'black'
#  5.  'white'
#  6.  'purple'
#  7.  'brown'
#  8.  'orange'
#  9.  'gray'

##</code><code>##

for (@array) {
	do_something_with($_, ++ state $i);
}

# Prints
#  1.  'red'
#  2.  'blue'
#  3.  'green'
#  4.  'yellow'
#  5.  'black'
#  6.  'white'
#  7.  'purple'
#  8.  'brown'
#  9.  'orange'
# 10.  'gray'

##</code><code>##

map { do_something_with($_, state $i++) } @array;