特定单词后读取数字

I'm trying to read a number in a link in php. But I'm not sure how to do it.

http://example.com/Productdetail.asp?SID=72&ProductID=8640

How can I read the number 8640 without reading 72 at the same time.

ProductID= <- it will always be there.

SID=X <- this one will be there sometimes and left out on other pages. and the number can change between 1-999,

Is there a way to say ProductID= "read the next 4 numbers and save in string"

Thanks

you can get this output by using explode()

$link='http://example.com/Productdetail.asp?SID=72&ProductID=8640';

    $links=explode('ProductID=',$link);
    echo $link[1]; //this is your number

Simple use

echo $_GET['ProductID'];//8640

You can use preg_match as

$str = "http://example.com/Productdetail.asp?SID=72&ProductID=8640";
preg_match('/&ProductID=(\d+)?/',$str,$match);
echo $match[1];

Or you can simply use parse_str as

$str = "http://example.com/Productdetail.asp?SID=72&ProductID=8640";
parse_str($str,$res);
echo $res['ProductID'];

You can use:

1. strpos to get the ProductID= 's index
2. substr to get the string from ProductID= until the end of the string
3. str_replace to replace the ProductID= part

    <?php
        $str = "http://example.com/Productdetail.asp?SID=72&ProductID=8640";    
        echo str_replace("ProductID=", "", substr($str, strpos($str, "ProductID=")));
    ?>