Using a regex is a little more compact:

use strict;
use warnings;

my $str = '12345678';

$str =~ s/(.)(.)/$2$1/g;

print $str;

[download]

Prints:

21436587

[download]

Update: BTW, using $a and $b as variables is a bad idea. They are the variables used by sort.

DWIM is Perl's answer to Gödel

In reply to Re: What is the best solution to swap input data? by GrandFather
in thread What is the best solution to swap input data? by bh_perl

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