I have an open source PHP website and I intend to modify/translate (mostly constant strings) it so it can be used by Japanese users.
The original code is PHP+MySQL+Apache and written in English with charset=utf-8
I want to change, for example, the word "login" into Japanese counterpart "ログイン" etc
I am not sure whether I have to save the PHP code in utf-8 format (just like Python)?
I only have experience with Python, so what other issues I should take care of?
If the file contains UTF-8 characters then save it with UTF-8. Otherwise you can save it in any format. One thing you should be aware of is that the PHP interpreter does not support the UTF-8 byte order mark so make sure you save it without that.
PHP for Python Programmers: UTF-8 Issues