The benefit of ordering the elements in a list array is that
we can easily grab one value out of the list on demand.
To do this, we use Perl's subscripting operator using the
When pulling an element out of a list array, we create a
scalar variable with the same name as the array, prefixed
with the usual dollar sign that denotes scalar variables.
For example, the first element of the array
@available_colors is accessed as $available_colors.
Notice that the first element is accessed with a zero. This
is important. List arrays begin counting at zero, not one.
Thus, $available_colors is a variable placeholder for
the word "red". Likewise, $available_colors equals
"green" and $available_colors equals "blue".