validate http:// or https:// using regex

You can validate http:// or https:// using the methods below:

$link = "http://site.com";  or $link = "https://site.com";
Example: My values would be either of the two, with or without "s".

Method 1:
echo preg_match("^(http(s?))://^", $link);  I prefer this method

Method 2:
echo preg_match("^(http|https)://^", $link);