map

Evaluates an expression for each element of a list:

@words = map {split ' '} @lines;

Here is another example. The variable $_ is temporarily set to each element of the list. Notice that the operation is destructive - @arr is changed.

my @arr = qw(1 2 3); 
my @new = map {$_ *= 2}  @arr;
print "@new, @arr\n"; # --> '2 4 6, 2 4 6'