Why preg_match_all forces me to provide the 3rd optional parameter?

Question

I'm counting the number of some special characters (like euro symbol) in `$text`, using `preg_match_all` and this regular expression: ``` preg_match_all('/[$$|$$|€\{|}|\|\^|\||~]/u', $text); ``` For some strange reason PHP asks me for a third parameter. But it's supposed to be optional as per documentation of preg_match_all: Warning: preg_match_all() expects at least 3 parameters, 2 given. If i provide `PREG_PATTERN_ORDER` (even don't know why should i) i get: Cannot pass parameter 3 by reference. So, what's wrong with my code? Here is the whole function if needed: ``` public function getMessageCount($text) { $specials = preg_match_all('/[$$|$$|€\{|}|\|\^|\||~]/u', $text) $characters = strlen($text) + $specials; if(in_array(strtolower($this->method), self::$classic_plans)) : if($characters >= 0 && $characters <= 160) return 1; if($characters >= 161 && $characters <= 306) return 2; if($characters >= 307 && $characters <= 459) return 3; if($characters >= 460 && $characters <= 612) ret…

Accepted Answer

Although 3rd parameter became optional in 5.4.0 like others have said already but your code doesn't compile even if you pass 3rd parameter because you said you pass PREG_PATTERN_ORDER flag but 3rd parameter is supposed to be the array that receives matches and 4th parameter is flag.

Use something like the following:

```
<?php
$dummy = array();
echo("Result = ".preg_match_all('/[$$|$$|x\{|}|\|\^|\||~]/', $text, $dummy));
?>
```

Why preg_match_all forces me to provide the 3rd optional parameter?

Solution

Problem