There is one additional "gotcha" when and if you split on whitespace... There is a difference in how leading whitespace is handled depending upon how you specify what to split upon. There is a difference between
' ' and / / or /\s+/. This is demo'ed below. Also shown is the -1 limit previously discussed although that limit does not affect this leading whitespace behaviour.
use strict;
use warnings;
use Data::Dump qw(pp);
my $str = " 1 2 3 "; # Note: leading whitespace in string...
# special behaviour when splitting on whitespace:
# leading null field:
my @with_regex = split (/ /,$str,-1);
pp \@with_regex; # ["", 1, 2, 3, ""]
@with_regex = split (/\s+/,$str,-1);
pp \@with_regex; # ["", 1, 2, 3, ""]
# no leading null field:
my @with_char = split (' ',$str,-1);
pp \@with_char; # [1, 2, 3, ""]
Update: I guess also worthy of mention, "", null string does not mean undef.