Can I store and call regex in variables for later use?

I plan on storing regular expression codes in a database, but not sure how to get t开发者_高级运维hem from a variable to function.

Any advise?

$i = "([wx])([yz])" 
$j = "[^A-Za-z0-9]" 
$k= "([A-Z]{3}|[0-9]{4})"

    //Wold this execute properly, this really is the extent of my question? 
    preg_match($i, $string);

Regular expressions are simply strings, so you could store them as such in your database.

It should work, the only thing you're missing are delimiters.

http://php.net/manual/en/regexp.reference.delimiters.php

When using the PCRE functions, it is required that the pattern is enclosed by delimiters. A delimiter can be any non-alphanumeric, non-backslash, non-whitespace character.

Often used delimiters are forward slashes (/), hash signs (#) and tildes (~). The following are all examples of valid delimited patterns.

/foo bar/
#^[^0-9]$#
+php+
%[a-zA-Z0-9_-]%

You could also store the expressions without delimiters and add them later.