Detecting IE8 and lower with PHP

Just yesterday I got myself an Xbox One (There may be a review on this coming soon). I tried out Internet Explorer on it, which I found out was Internet Explorer 10.

I also discovered that my PHP script to detect Internet Explorer 8 accepted Internet Explorer 10 as being an older version than Internet Explorer 8. This is a simple mistake to make but it's also incredibly easy to fix.

Here was what I had:

preg_match("/.* MSIE [1-8] .*/i", $userAgent)

And here is a working solution, to detect all browsers less than IE8:

preg_match("/.* MSIE [1-8].[0-9]?; .*/i", $userAgent)

And the reason for this happening is down to the fact this only checks the first number of the version, not the second, so IE10 would be recognised as IE1. I also put in, just for the sake of it, a check for a dot (.) and a check for a minor version number ([0-9]) and a semi-colon at the end. At the beginning and end of the regular expression match are any symbols.