sub foo {

    my @arra = ('a' .. 'z');
    my @arrb;
    for ( 0 .. ( $#arra - 1) ) {
        bar($_);
    }
    
    bar($#arra);

    sub bar {
        my ($i) = @_;

        push @arrb, $arra[$i];
        
    }

    return \@arrb;
}