function clean_number($string, $flags='') {
	$comma = $decimal = $minus = true;
	$parsedFlags = (count(explode(' ', $flags)) > 0 ? explode(' ', $flags) : $flags);
	$allowed = array('NO_COMMA', 'NO_DECIMAL', 'NO_MINUS', 'NUMBERS_ONLY');
	if (is_array ($parsedFlags)) {
		foreach ($parsedFlags as $explodedflag) {
			if (in_array ($explodedflag, $allowed)) {
				switch (strtoupper ($explodedflag)) {
					case 'NO_COMMA':
						$comma = false;
						break;
					case 'NO_DECIMAL':
						$decimal = false;
						break;
					case 'NO_MINUS':
						$minus = false;
						break;
					case 'NUMBERS_ONLY':
						$comma = false;
						$decimal = false;
						$minus = false;
						break;
				}
			}
		}
	}
	$pattern = "/[^0-9".($comma ? "," : "").($decimal ? "." : "").($minus ? "-" : "")."]+/";
	return preg_replace ($pattern, "", $string);
}

# Examples:
$serialnumber = clean_number('SRV293-26731-853-US170711', "NUMBERS_ONLY");
$otherCountries = clean_number('1.542.765,23');
$usCurrency = clean_number('$5,235.95', "NO_COMMA");
$removeMinus = clean_number('-4', "NO_MINUS");
$removeDecimal = clean_number('48.63', "NO_DECIMAL");
$anotherTest = clean_number('-36,326.54', "NO_COMMA NO_MINUS NO_DECIMAL");

echo $serialnumber; # output 29326731853170711
echo $otherCountries; # output 1.542.765,23
echo $usCurrency; # output 5235.95
echo $removeMinus; # output 4
echo $removeDecimal; # output 4863
echo $anotherTest; # output 3632654
echo clean_number('4f32k91025'); # output 43291025

    $dataset = array(
        "John Adams"=>"SD546-236",
        "William Smith"=>"RQ547-236",
        "Jazz Reynolds"=>"FG542-459",
        "Kimberly Stien"=>"RF321-865",
        "Ian Williams"=>"GG655-962",
        "Frances Teiger"=>"YN653-566",
        "Lynn Merasol"=>"BG345-679",
        "James Deeter"=>"NB654-234",
        "Adrian Monk"=>"CA654-645"
    );

    echo "<table style=\"margin: 1em 0; background-color: #f8f9fa; border: 1px solid #a2a9b1; border-collapse: collapse; color: #000;\">";
    echo "<thead style=\"display: table-row-group; vertical-align: middle; border-color: inherit;\">";
    echo "<tr style=\"display: table-row\">";
    echo "<th style=\"background-color: #eaecf0; text-align: center;\">Customer Name</th>";
    echo "<th style=\"background-color: #eaecf0; text-align: center;\">Customer ID</th>";
    echo "</tr>";
    echo "</thead>";
    echo "<tbody>";
    foreach ($dataset as $id=>$data){
        echo "<tr style=\"display: table-row\">";
        echo "<td style=\"border: 1px solid #a2a9b1; padding: 0.2em 0.4em;\">".$id."</td>";
        echo "<td style=\"border: 1px solid #a2a9b1; padding: 0.2em 0.4em;\">".clean_number($data, "NUMBERS_ONLY")."</td>";
        echo "</tr>";
    }
    echo "</tbody>";
    echo "</table>"