问题
I am trying to write a regex pattern in Java to detect if a user agent is less than or equal to Internet Explorer 9. There are quite a few examples here:
http://www.useragentstring.com/pages/Internet%20Explorer/
The main gist is there will be a string in the user agent string called: "MSIE XXXX). My current regex pattern is this:
MSIE ([1-9]|9)
Which seems to work except there are problems when I do MSIE 10.0 or MSIE 11.0 it matches. Any ideas on how to only match 1-9 and no 10.0 or 11?
回答1:
In old versions, there is always a dot after the major version number, you can use it in your regex :
MSIE [1-9]\.
Another way to write it is to expect one number between 1 and 9 followed by a non number char :
MSIE [1-9][^0-9]
回答2:
only match 5-9 and not 1-9. There are virtually 0 people using IE 4 and below.
来源：https://stackoverflow.com/questions/27239932/regex-to-detect-ie9-and-below