Help with complex regular expression

Currently I am using two foreach functions to put defined characters before and after a string (I use them as word separators - examples: " string.", " string ", "(string)" etc.). It looks like this:

foreach(){
           foreach(){ 
                    $needle = $separator . $string . $separator_end;
                    preg_match($needle, $haystack);
          }
}

Code (markup):

But this way of doing it isn't really effective. Do you have any idea how to put these separators (I store them in a database - they can be changed any time) to the regular expression to make it work?

 

Does anybody know?

 

Can you post the before and after strings?

 

Sure.

 .,?!:;'"`/()[]{}_+ =-<>~@#$%^&*

Code (markup):

The problem is that users may specify different separators, so I need to load them from a database - they must not be hardcoded.

 

Let me attempt to clarify your issue before I attempt a solution:

You have a string:

"same string, to be split"

You want it to be split into an array by the comma:

same string
to be split

However, you want to be able to do it with more than just the comma, but with any of the strings:

.,?!:;'"`/()[]{}_+ =-<>~@#$%^&*

Plus additional ones from the db. Is my analysis correct?

 

I don't need to add it to an array I just need to determine if a word with any combination of separators in my DB is present in a string. I am using 2 foreachs and preg_match to do that but I think that it can be done by using a single regexp without these loops. Any idea how to accomplish that?

 

Ok. I think I understand your question now. You want to know if any characters in string A exists in string B.

// Match any of these chatacters
$stringOne = '.,?!:;\'"`/()[]{}_+=-<>~@#$%^&*';

// Split by letter
$stringOne = str_split($stringOne);
$matchMe = '';

// Add | (OR) between the letters, quoting those characters needing quoting
foreach ($stringOne as $string) { 
    $matchMe .= preg_quote($string) . '|';
}
// Remove last extra | character
$matchMe = substr($matchMe, 0, -1);
unset($stringOne);

// Actual match
$stringTwo = 'A string that might contain or not something from the above list in this case it does!';
if (preg_match('$' . $matchMe . '$', $stringTwo)) {
    echo 'match found';
} else {
    echo 'no match found';
}

PHP:

Hope this is what you are looking for.

 

Thank you. I replaced the preg_match function with the following row, it should be able to find words with separators now:

preg_match('$(' . $matchMe. ')word('. $matchMe .')$', $stringTwo)

Code (markup):

I am just curious, why did you use the unset function? I know what it does but I really don't know why did you put it there.

 

You can call it a habit. I always unset variables that I do not need to use. Shouldn't make much difference on your side.