Question

Looking for a reg ex to null (empty) the string if it any contains the bad word..

    $string1 = "Ihatestackoverflow";
    $string2 = "I HaTe sackoverflow";
    $string3 = "1HaTestackoverflow";

    $badword = "hate";

# result
# string1 = "";
# string2 = "";
# string3 = "";

Answer 1

$regex = '#^.*?(hate).*$#ims';
$str = preg_replace($regex, '', $str);

To add more “bad words”, just add them in the ():

$regex = '#^.*?(hate|anotherbadword|yetanother|etc).*$#ims';

The leading ^ and trailing $ match the full string. The i option is for case insensitive matching. The m enables multi-line mode (so that ^ and $ match the whole string, as opposed to a single line in it). The s enables DOTALL (so the . matches new line characters as well).

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