$re = '/City:\s*(?P<City>[^,]+?)\s*,\s*Zip:\s*(?P<Zip>\d+)/m';
$str = 'Zip Code Details: City: Huntsville_Alabama , Zip: 35808 , 801thru816 City: Anchorage_Alaska , Zip: 99506
Zip Code Details: City: Miami_Florida , Zip: 33128 , 124thru190 City: Atlanta_Georgia , Zip: 30301 , 301thru381';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php