On Monday 05 November 2007 09:47, Patrik Hasibuan wrote:
> Dear my friends...
Hello,
> I am exhausted by a programming case which may be easy for you all. I
> am trying to remove all the space (empty character) in a
> variable($k_tmp) in order to put them in an array, one cell only for
> one word. The value of the variable ($k_tmp) is a page of google
> which I did using "UserAgent".
>
> For identifying whether it's an 'empty displayed' value, I do so:
> foreach my $k_tmp(@kalimat){
> $spasi=0;
> @k=split(" +",$k_tmp);
We usually delimit regular expressions with // instead of "".
> #####hapus sel berisi spasi######
> foreach $k_tmp(@k){
You are using the same variable name ($k_tmp) as the outer foreach
loop. You should use a different name and use my() to make it a
lexical variable.
> my $spasi=$k_tmp=~/ +/g;
Because of the split() above there will be no space characters in
$k_tmp and $spasi will *always* be false.
> my $garisbaru=$k_tmp=~/\n+/g;
The expression $k_tmp=~//g in scalar context will return true or false
(1 or ''). The expression /\n/ would be more efficient than /\n+/g
(because 1 "\n" character is just as true as 1,000 "\n" characters.)
Or you could use index() instead.
> unless($spasi==1 or $garisbaru==1){
> push(@k_isi,$k_tmp);
> }
> }
So @k_isi will only contain strings that don't have a "\n" in them:
my @k_isi = grep !/\n/, split / +/, $k_tmp;
> #end of 'hapus sel berisi spasi'#
> $spasi=0;
> push(@kata,@k_isi);
> [EMAIL PROTECTED];
> splice(@k,0,$z);
Or just:
@k = ();
> [EMAIL PROTECTED];
> splice(@k_isi,0,$z);
Or just:
@k_isi = ();
Or you could push() *and* clear out the array at the same time:
push @kata, splice @k_isi;
> }
>
> But my program give output how I can not understand. I still have
> 'empty displayed' value of a variable in '@k_isi'.
>
> As far as I know, the sort of data/character/string those displayed
> empty space are only space (' ') and newline ('\n').
>
> Please tell me if there is still other "things" which will be
> diplayed empty by "print $var".
It sounds like you are getting a warning about an uninitialized value,
something like:
$ perl -Mwarnings -le' my $x; print "$x" '
Use of uninitialized value in string at -e line 1.
perldoc -f undef
perldoc -f defined
When you use split:
@k=split(" +",$k_tmp);
and $k_tmp contains space characters at the beginning like " some
text" then the array @k will have a zero length string at the beginning
like ( '', 'some', 'text' ) and that could be the 'empty displayed'
value you are seeing.
John
--
use Perl;
program
fulfillment
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