Youtube Api Duration to Seconds

parse_duration.php

function parse_duration($duration, $resultType){

	$matches = array();
	preg_match('/^(-|)?P([0-9]+Y|)?([0-9]+M|)?([0-9]+D|)?T?([0-9]+H|)?([0-9]+M|)?([0-9]+S|)?$/', $duration, $matches);
	if(!empty($matches)){       

		foreach($matches as &$match){
			$match = preg_replace('/((?!([0-9]|-)).)*/', '', $match);
		}   
    
		switch ($resultType) {

			case 'second':
				return ($matches[6]*60)+$matches[7];
			break;

			case 'minute':
				return $matches[6].':'.$matches[7];
			break;

		 } 

	}
	else{
		return false;
	}

}

print_r(parse_duration('PT18M21S','second'));