Question

OK, I know how to do this but I’m interested in better/more elegant solutions (if any) for this problem.

Imagine I have the following string :

Mozilla/4.0 (compatible; MSIE 7.0;
Windows NT 5.1; Trident/4.0; GTB6.6;
Mozilla/4.0 (compatible; MSIE 6.0;
Windows NT 5.1; SV1) ; .NET CLR
1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)

I’m interested to find the highest MSIE version in that string (in that case 7.0).

Currently I use explode and preg_match a couple of times in combination with str_replace then I loop between matches and then compare the version string. It works but it’s far from elegant. Any ideas on how to improve this?

Keep in mind that:

• The string can have any number of MSIE occurrences (or even none)
• MSIE is case insensitive
• MSIE is followed by a white space (space, tab…) then by the version. The version can contain number letters and dots. The version string is ended by either a white space, a ; or the end of the line.

Thanks!

Answer 1

Try:

<?php
$str = 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; GTB6.6; Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1), MSIE 8.7abc; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729) MSIE 9.0';

if (preg_match_all('/msie\s*([^\s;$]+)/i', $str, $m)) {
    usort($m[1], 'version_compare');
    $max = array_pop($m[1]);

    echo $max;
}