How can regular expressions be used to extract specific date formats from a string in PHP?

Regular expressions can be used to extract specific date formats from a string in PHP by defining a pattern that matches the desired date format. This pattern can include placeholders for different components of a date, such as day, month, and year. By using functions like preg_match() or preg_match_all(), we can search the input string for dates that match the specified pattern and extract them for further processing.

$input_string = "Today is 01/25/2022 and tomorrow will be 26-01-2022.";
$date_pattern = "/\b\d{2}[\/-]\d{2}[\/-]\d{4}\b/";

preg_match_all($date_pattern, $input_string, $matches);

foreach ($matches[0] as $date) {
    echo $date . "\n";
}