for-loop-map-prefix

use feature qw(say);
use strict;
use warnings;

my @abc = ('1234.txt', '2345.txt', '3456.txt', '4567.txt');
my @xyz;
for my $abc (@abc) {
    my ($prefix) = $abc =~ /(\d*).txt/;
    say "$prefix";
    push @xyz, $prefix;
}