What does this little arrow and "no" symbol to the right of "get_footer(); ?>" mean?
mgarciaisaia
It's the no-newline octicon. It tells you that your file doesn't have a trailing newline.
You can read about why that is important to note in this question.
来源：https://stackoverflow.com/questions/34271528/what-is-little-red-arrow-and-no-sign-in-github-desktop