HP Prime

[Han]

(09-06-2014 03:01 AM)gbh Wrote:  (1) What does putting a variable in single quotes (e.g., 'X') mean, and why?

I think this is the same as that for the HP48: 'X' is the variable itself, whereas X produces the contents of the variable. (Perhaps I misunderstand your question)

Quote:(2) == AND = are supposedly different, but = seems to work where == ostensibly would be required; e.g., (n=2) returns 1. Are = and == equivalent in some contexts and not others?

Unfortunately, yes. The CAS environment sometimes handles = as ==.

Quote:(3) Are := and the little right-pointing arrow (Store) always equivalent, or just sometimes?

They are two different ways of doing exactly the same thing. The := syntax is much easier for those creating code on a PC (whose keyboard lacks the right-pointing arrow) whereas the arrow is readily accessible on the calculator (either via the menu or keystrokes).

Quote:(4) How to declare "locally global" variables and functions---those to be shared by all the subroutines of a program (without passing arguments in parentheses). Evidently such variables and functions are declared before the first Export Func() statement. I had to figure this out from examples on the internet, and I'm not sure I really understand it. A few sentences in the manual would clarify the procedure.

They just need to be declared before the function calling them, like with C/C++ functions. You do not necessarily have to declare before the first instance of EXPORT.

Here's my understanding of it: http://www.hpmuseum.org/forum/thread-216.html