Regular expression to detect Internet Explorer 11

Question

I am using this preg_match string

preg_match(\'/Trident/7.0; rv:11.0/\',$_SERVER[\"HTTP_USER_AGENT\"]

to detect IE11 so I can

Answer 1

Is this really a regular expression or just a literal string? If it's just a string, you can use the strpos function instead.

if (strpos($_SERVER['HTTP_USER_AGENT'], 'Trident/7.0; rv:11.0') !== false) {
    // your code
}

If it's a regular expression, you must escape special characters like / and .

EDIT:

You can see in the comments of this answer that the code doesn't detect IE 11 properly in all cases. I didn't actually test it to match it, I've just adjusted the code of the question creator to use strpos instead of preg_match because it was applied incorrectly.

If you want a reliable way to detect IE 11 please take a look at the other answers.