#!/usr/bin/perl

use strict;
use warnings;
use Tk;

my $mw = tkinit();
my @radiobuttons;

for ( 1 .. 5 ) {
    my $var;
    my $rb = $mw->Radiobutton( -variable => \$var, -text => $_, -value => $_ );
    $rb->pack;
    
    push @radiobuttons, $rb;
}

$radiobuttons[3]->select;

MainLoop;