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, ""]
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Update: I guess also worthy of mention, "", null string does not mean undef.