Question

as we know, return keyword will RETURN some value and exit current function. Mean, that this one used only inside some functions.

BUT, I saw some php-dev’s use return keyword outside functions, even in index.php file (in root of web server). What is that mean???? By the way, maybe it’s logical to require some file inside function, but this style isnt mine.

Answer 1

There’s not much more to say than what the docs do.

About the common usage of return:

If called from within a function, the return statement immediately
ends execution of the current function, and returns its argument as
the value of the function call. return will also end the execution of
an eval() statement or script file.

About the less common usage:

If called from the global scope, then execution of the current script
file is ended. If the current script file was included or required,
then control is passed back to the calling file. Furthermore, if the
current script file was included, then the value given to return will
be returned as the value of the include call. If return is called from
within the main script file, then script execution ends. If the
current script file was named by the auto_prepend_file or
auto_append_file configuration options in php.ini, then that script
file’s execution is ended.