Modifying Class Object

[Steven D'Aprano]

On Mon, 08 Feb 2010 03:21:11 +0100, Alf P. Steinbach wrote:

>> A pointer tells you where something is; a reference doesn't.
> 
> Sorry, I don't know of any relevant terminology where that is the case.

Taken from Wikipedia:

"A pointer is a simple, less abstracted implementation of the more 
abstracted reference data type (although it is not as directly usable as 
a C++ reference)."

http://en.wikipedia.org/wiki/Pointer_(computing)

In other words, a pointer is a specific type of reference. A reference in 
turn is an opaque but low-level data type which "refers to" in some way 
to the data you actually care about. (C++ has a concrete reference type, 
which is not to be confused with abstract references.)

http://en.wikipedia.org/wiki/Reference_(computer_science)

Unless otherwise stated, references are opaque and coders need not care 
how the reference mechanism is implemented, see e.g.:

http://www.cocoabuilder.com/archive/cocoa/20777-opaque-reference.html

In Python you don't use references directly, there is no reference type 
or object. You can simulate the semantics of references (but not 
pointers) by putting your object in a list and passing the list around.



-- 
Steven