Check If string contains any of the words

Question

I need to check if a string contains any one of the banned words. My requirements are:

1. Case insensitive which is why I used stripos()
2. Word should be separated by spaces, for example if banned word is "poker", "poker game" or "game poker match" should come under banned string and "trainpokering great" should come under good string.

I have tried something like below

$string  = "poker park is great";

if (stripos($string, 'poker||casino') === false) 
{

echo "banned words found";
}
else

{
echo $string;
}

Answer 1

Use preg_match to match a regular expression:

$string  = "poker park is great";

if (preg_match("/(poker|casino)/", $string)) {
  echo "banned words found";
} else {
  echo $string;
}

UPDATE: As suggested in comments and in Mayur Relekar answer, if you want your match to be case-insensitive, you should add an i flag to your regex.
And, if you want to match words (i.e., "poker" should be preceded and followed by a word-boundary, for example a space, a punctuation, or an end-of-file), you should enclose your matching group with \b...
So:

...
if (preg_match("/\b(poker|casino)\b/i", $string)) {
...

Answer 2

MarcoS is right, except that in your case you need to match the exact string and not an unbound string. For this, you need to prefix and suffix \b (\b is a word delimiter) to the string you want to exactly match.

$string  = "poker park is great";
if (preg_match("/\bpoker\b/", $string)) {
    echo "banned words found";
} else {
    echo $string;
}

Answer 3

$string  = "park doing great with pokering. casino is too dangerous.";
$needles = array("poker","casino");
foreach($needles as $needle){
  if (preg_match("/\b".$needle."\b/", $string)) {
    echo "banned words found";
    die;
  }
}
echo $string;
die;

Answer 4

You could use an array and join it

$arr = array('poker','casino','some','other', 'word', 'regex+++*much/escaping()');
$string = 'cool guy';

for($i = 0, $l = count($arr); $i < $l; $i++) {
    $arr[$i] = preg_quote($arr[$i], '/');   // Automagically escape regex tokens (think about quantifiers +*, [], () delimiters etc...)
}
//print_r($arr); // Check the results after escaping

if(preg_match('/\b(?:' . join('|', $arr). ')\b/i', $string)) { // now we don't need to fear 
    echo 'banned words found';
} else {
    echo $string;
}

It uses word boundary and joins the array.