use strict;
use warnings;

my $str='1,zxc,2,asd,3,qwe';
foreach ( $str =~ /([^,]+,[^,]+)/g ) {
  my ($k, $v) = split /,/;
  print "Do something with key $k and value $v\n";
}

##</code><code>##

foreach (my ($k,$v) = $str =~ /([^,]+),([^,]+)/g) {