get_instance() in Codeigniter: Why assign it to a variable?

Question

In Codeigniter, get_instance() is a globally available function that returns the Controller super-object which contains all the currently loaded classes (it ret

Answer 1

Why is it recommended to assign get_instance() to a variable rather than calling it directly?

Most probably, it is recommended to maintain backward compatibility with php4, where objects were not passed by reference by default, but were cloned.

Is there any reason not to take this approach?

Only if you want your application to run on outdated php installations