how to check exact match in regex code example

Example 1: regex match exact string

you want to achieve a case insensitive match for the word "rocket" 
surrounded by non-alphanumeric characters. A regex that would work would be:

\W*((?i)rocket(?-i))\W*

Example 2: regex exact match

use ^ and $ to match the start and end of your string
^matchmeexactly$