Unicode identifiers (function names) for non-localization purposes advisable?

Question

PHP allows Unicode identifiers for variables, functions, classes and constants anyhow. It was certainly intended for localized applications. Wether it\'s a good idea to code

Answer 1

Just to make it clear: PHP does not support Unicode. And it doesn't support Unicode labels. To be more precise PHP defines a LABEL as [a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*. As you can see here, it allows only a small range of characters apart from the typical alphanumeric + underscore. The fact that your Unicode labels are still accepted is only an artifact from the fact, that PHP doesn't have Unicode support. Your special characters are several bytes long in UTF-8 and PHP treats each of these bytes as a separate character and accidentally - with the characters you tried - each of them matched with the \x7f-\xff range mentioned above.

Further reading on that topic: Exotic names for methods, constants, variables and fields - Bug or Feature?