The following word must not be in a string

[Lumio]

Hello,

I have a little problem with regular expressions.

 

I got the following string:

$str = "PLAIN";

 

So what I want to do now is to say, that if the string is PLAIN, that it is not true, but with a regular expression.

 

I tried

<?php
$str = "PLAIN";
$r = "^PLAIN";

var_dump(preg_match("/($r)/", $str));

But it always gets 1 and not 0. Why?

[.josh]

You are only getting 1 or 0 because preg_match returns a true on successful match, false on no matches when you assert it in a condition like that (or assign it to a var).  Actual results would be put into the 3rd argument of preg_match. 

 

Beyond that....be more specific.  Are you wanting to dump out the contents of $string if it is not "PLAIN" or if it does not contain "PLAIN" in it somewhere? Or are you simply trying to find out whether it is or contains "PLAIN"?

[Lumio]

Hi!

Thanks for your quick answere.

Well I do have more keywords like that.

For example K_IF or K_ELSE or K_ENDIF.

 

Let's say, I only want to let a condition get true, if it is not PLAIN. Okay, for that reason I can use a normal if-statement. But lets say I don't want to have lets say PLAIN and also not K_ENDIF. So I thought ^PLAIN|^K_ENDIF would do it, but no. It doesn't

 

I want to match the whole key.

[.josh]

Okay but are those "keywords" the only thing in the string like

 

"PLAIN"

"K_IF"

etc..

 

or are they just one piece of a string like

 

"PLAIN blahblahlbha"

"blah PLAIN blahblah"

 

And again, are you trying to retrieve something from somewhere or are you simply trying to find out whether it's true or not.

[Lumio]

No, they are the only one. Without any other text.

[.josh]

okay so then you can just do this:

 

$list = array('PLAIN','K_IF','K_ELSE','K_ENDIF');
if (!in_array($string, $list)) {
   // string is not one of those things, do something
} else {
  // string is one of those things, do something
}

[Lumio]

is that quicker?

but what if I want to say everythink but not PLAIN?

[.josh]

then just do

 

if ($string != "PLAIN") {
  // string not plain, do something
} else {
  // string is plain, do something
}

 

Yes, straight string comparison is faster than regex.