How can PHP developers ensure that a specific word pattern is not followed by certain characters in a text?

To ensure that a specific word pattern is not followed by certain characters in a text, PHP developers can use regular expressions with negative lookahead assertions. By defining a pattern that matches the word pattern followed by the disallowed characters, developers can use the negative lookahead assertion to ensure that the pattern is not followed by those characters. 

$text = "This is a sample text with the word pattern123 and pattern456 but not followed by characters !@#";

$pattern = '/pattern\d+(?![!@#])/'; // Match 'pattern' followed by digits not followed by !, @, or #

$filtered_text = preg_replace($pattern, '', $text);

echo $filtered_text;

Keywords

PHP regular expressions preg_match negative lookahead character class

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