Interestingly, using length join is pretty fast: 
#!/usr/bin/perl
use warnings;
use strict;

use List::Util qw{ sum };
use Benchmark qw{ cmpthese };
use Test::More tests => 1;

my @arr = ('abc', 'cd', 'e', 'fg', 'hi', 'hello world');

sub xsum  { sum(map length, @arr) }
sub xjoin { length join "", @arr }

warn xsum();

is xsum(), xjoin(), 'same';

cmpthese(-3, {
    sum  => \&xsum,
    join => \&xjoin,
});

[download]

Output: 

1..1
21 at ./2.pl line 14.
ok 1 - same
          Rate  sum join
sum  1470509/s   -- -77%
join 6267577/s 326%   --

[download]

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In reply to Re: How to get the TOTAL length/size of an array? by choroba
in thread How to get the TOTAL length/size of an array? by Polyglot

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