cyberRobot Posted January 5, 2010 Share Posted January 5, 2010 I'm using preg_match to compare new user input to an existing database entry. What I have works for the most part but I ran into an issue when that user input contains special characters like parenthesis. Is there a function available to escape these characters? Or maybe there's a way to tell PHP to treat what's inside a variable as text only? For example, here is a simplified version of what I was using to test a phone number: if(preg_match("/^$newPhoneNum$/i", $databasePhoneNum)) { //DO NOTHING } else { //CREATE A BUTTON THAT UPDATES THE DATABASE } The above code doesn't work if $newPhoneNum is equal to "(888)888-8888" due to the parenthesis. So I modified the code to be: $newPhoneNum = preg_replace("/[^a-zA-Z0-9]/", '', $newPhoneNum); $databasePhoneNum = preg_replace("/[^a-zA-Z0-9]/", '', $databasePhoneNum); if(preg_match("/^$newPhoneNum$/i", $databasePhoneNum)) { //DO NOTHING } else { //CREATE A BUTTON THAT UPDATES THE DATABASE } The new code not only solved the issue with parenthesis, but it also matches phone numbers like "888-888-8888", "(888) 888-8888", etc. But I still could have problems with the other fields (name, address, etc.). Is there another solution that I'm missing, or do I need to keep using things like preg_replace to remove troublesome characters? :-\ Quote Link to comment Share on other sites More sharing options...
thebadbad Posted January 5, 2010 Share Posted January 5, 2010 preg_quote() is made for this And remember to feed your delimiter as the second parameter. Edit: But if you only want to do a case-insensitive comparison, the below will suffice (and be faster): <?php if (strtolower($newPhoneNum) == strtolower($databasePhoneNum)) { //match } ?> or probably even <?php if (strcasecmp($newPhoneNum, $databasePhoneNum) == 0) { //match } ?> Quote Link to comment Share on other sites More sharing options...
cyberRobot Posted January 5, 2010 Author Share Posted January 5, 2010 Thanks for the excellent tips. I'm not sure why I didn't think about using strtolower(). I'll most likely switch to that. Quote Link to comment Share on other sites More sharing options...
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