How can I check for a plus sign using regular expressions?

Question

I'm trying to check for a plus sign using PHP and regular expressions.

Here is the code I got so far.

preg_replace('#[^-a-zA-Z0-9_&; ]#', '', $abcd)

Answer 1

Add a + to the list.

preg_replace('#[^-a-zA-Z0-9_&; +]#', '', $abcd)

Answer 2

You might just need to escape the plus sign with a backslash: \+.