Preg replace special characters

Hi I want to delete this character: | with php preg replace. My code do n开发者_运维知识库ot work

$rstr = '|||is';
$Grab->text = preg_replace($rstr,'',$Grab->text);
echo $Grab->text;

---

If you really waht to use a regular expression, you need to escape the | character, which as a special meaning :

$Grab->text = preg_replace('#\|#is', '', $Grab->text);

This is supposing you only want to replace one |, and not three in a row -- in which case you'd use :

$Grab->text = preg_replace('#\|{3}#is', '', $Grab->text);

Also note that I used # as delimiters -- it's easier to write/read the regex when delimiters are not characters that are present inside the regex : less escaping to do.

But, as @Pekka noted in his comment to your question, why not just use str_replace() ?

$Grab->text = str_replace('|', '', $Grab->text);

Or, if you only want the replacement to be made when there are three | :

$Grab->text = str_replace('|||', '', $Grab->text);

After all, in a simple case such as this one, there is no need for regular expressions.

---

| is a regex meta-character, and you also use it as the delimiter (and that's 2 problems). You should escape the | sign, and use another delimiter (you also don't need the i and s flags):

$rstr = '~\|~';

Your regex was interpeted as ~~|is, and had the following error message:

Warning: preg_replace(): Unknown modifier '|' in /home/o3oYmU/prog.php on line 3

---

| has special meaning in a regex, it is used for alternation (ie a|b|c means a or b or c) so you have to escape it :

$Grab->text = preg_replace("/\|\|\|is/",'',$Grab->text);

or double escape if you assing a string $rstr = '\\|\\|\\|is';