On the MyBuilder.com Tech blog Edd Mann has a post sharing some advice about dealing with newlines and Unicode characters in both Javascript and PHP functionality.

We were recently sent a tweet in-regard to a text-area client/server-side length validation not correlating. After some detective work we were able to find two issues that could have caused this to occur. In this post I wish to discuss our findings, and how we resolved each issue.

The first issue they found was newline characters that didn't seem to be there by normal ACSII standards in text-area inputs. They were showing as a single character on the client where it was two on the server, later discovered to be a defined standard in the HTML 5 spec. The second Unicode-related issue was with characters outside of the basic multilingual plane and how Javascript measures its length. The post then explains their solutions to each of the two issues, doing some string replacement and using a different function to get the length of a string.