^M is the dos carriage return that's left after each line when you move a file from a Windows box to a *NIX box. I know how to remove it. I am curious to know is there any other reason besides aesthetics that it should be removed from a PHP script.
The PHP script runs fine with it in. Normally, I would remove it without hesitation, but don't want to have my name next to each line in an svn blame command. (besides the point).
Question: Is there a reason in regards to functionality of why it should be remove other than aesthetics? It doesn't seem to break anything to keep it in. (Give me a good reason plz)
All in all, it should be fine. Other languages are picky about their line endings; I've seen it cause issues in Perl scripts, for example. But for PHP, i've never seen it matter much.
One occasion where it could conceivably matter is in multi-line strings, where the extra chars would make it through to the output. This might matter if your output is not HTML or XML. But JS shouldn't be particular about extraneous CRs, and HTML and XML will generally treat any whitespace the same as a single space (or in many cases, disregard whitespace altogether). Textareas and <pre> elements and such might end up with extra whitespace in them. That's about the only issue i can think of.