> I don't fully understand how, when or why to use the map function -
>
> my @file = ("line 1", "line 2", "line 3", "line 4", "line 5");
> my @test = map {/5/} @file;
>
> The result when I print @test is:
> 1
>
> As I understand things, this is the m/5/ being "true"
Sorta. It's the length of the list resulting from map.
Which is one.
> Would it be fair to say we would use map when we
> expect to have the expression return a list?
Well, grep does that too.
Grep:
foreach element
do match
if match, add matched item to result list
If you grep against a 10 element list, you
get from zero to ten elements back.
Map:
foreach element
do something
add list of something's results to result list
If you map against a 10 element list, you
get from zero to infinite (sorta) elements back.
> How would I go about creating a second array using map
> or grep without changing the original? Can I do that at all?
@foo = @bar;
