while (1) {
    ...
}

##</code><code>##

while (1) {
  say $1;
}

##</code><code>##

use strict;
use warnings;
use 5.012;

if ('aXaYaZ' =~ /(a[XYZ])/ ) {
    say $1;
}

--output:--
aX


##</code><code>##

my @matches =  'aXaYaZ' =~ /(a[XYZ])/g; 
say "@matches";

--output:--
aX