sub join1 {
    my( $sep, @vals ) = @_;
    my $str = '';
    while( @vals ) {
        $str .= shift @vals;
        $str .= $sep
            if  @vals;
    }
    return $str;
}

sub join2 {
    my( $sep, @vals ) = @_;
    $sep = "$sep";        # Added
    my $str = '';
    while( @vals ) {
        $str .= shift @vals;
        $str .= $sep
            if  @vals;
    }
    return $str;
}