What are the advantages and disadvantages of using regular expressions versus string functions in PHP for text extraction?

Regular expressions are powerful tools for pattern matching and text extraction in PHP. They allow for more complex and flexible matching criteria compared to simple string functions. However, regular expressions can be more difficult to understand and maintain, especially for beginners. String functions, on the other hand, are easier to use and understand but may not be as powerful or versatile as regular expressions.

// Using regular expressions for text extraction
$text = "The quick brown fox jumps over the lazy dog.";
$pattern = '/quick brown (\w+)/';
preg_match($pattern, $text, $matches);
echo $matches[1];

// Using string functions for text extraction
$text = "The quick brown fox jumps over the lazy dog.";
$substring = substr($text, strpos($text, 'quick brown') + strlen('quick brown'));
$word = substr($substring, 0, strpos($substring, ' '));
echo $word;