Question

I got a contact form, I need to filter some words.

I’m doing it as following:

$array = array('lorem', 'ipsum', 'ip.sum');
for($i = 0; $i < count($array); $i++)
        {
            if( preg_match("/".$array[$i]."/", (string) $field) )
            {
                return false;
            }
        }

I’m not a regex master, but it should be working for words like: lorem or ipsum. But it is not.

BTW. Any suggestions how to catch mispelled words, ex. i.psum, l.o.rem?

Update
Of course, I have no empty pattern, I just forgot to paste it.

Update 2
I’ve decided to got the way suggested by Daniel Vandersluis. Abnyway, I’m not able to make it working.

$field = "ipsum lorem"; // This value comes from textarea
$array = array('ipsum', 'lorem', 'ip.sum');
foreach($array as $term):
    if(preg_match('/'.preg_quote($term).'/', $field)) {
        return false;
    }
endforeach;

Any ideas?

Answer 1

If I understand correctly, and you want to see if any of the words in your array are in your field, you can do something like this:

function check_for_disallowed_words($text, $words)
{
  // $text is the text being checked, $words is an array of disallowed words
  foreach($words as $word)
  {
    if (preg_match('/' . preg_quote($word) . '/', $text))
    {
      return false;
    }
  }

  return true;
}

$array = array('lorem', 'ipsum', 'ip.sum');
$valid = check_for_disallowed_words($field, $array);

In your example, you weren’t defining any pattern to be used. preg_quote will take a string and make it ready to use in a regular expression (because, for example, the dot in ip.sum actually has special meaning in a regular expression so it needs to be escaped if you want to search for a literal dot).

As an aside, if you’d like to learn more about regular expressions, take a look at the tutorial on regular-expressions.info, it is very in depth.