Finding the instance reference of an object

Aaron Brady castironpi at gmail.com
Mon Nov 3 22:36:01 CET 2008


On Nov 3, 2:44 pm, Joe Strout <j... at strout.net> wrote:
> On Nov 3, 2008, at 12:00 PM, Aaron Brady wrote:
>
> > I think we can conclude that Python passes by reference, since a
> > function can modify objects that were passed in to it.
>
> Then please write the Python equivalent of the "Swap" methods shown at  
> <http://www.strout.net/info/coding/valref/> (or at <http://javadude.com/articles/passbyvalue.htm
>  >, for that matter).
>
> And no fair wrapping the two parameters up in an object or using tuple  
> packing/unpacking -- the point is to demonstrate that you can change  
> the two parameters themselves, not some object that contains them or  
> return them a different order.
>
> And by the way, if mutating an object a parameter refers to qualifies  
> as pass by reference, then Java, VB.NET/REALbasic (in ByVal mode), and  
> C/C++ all pass by reference too.  That'll be quite a surprise to their  
> compiler authors!  (I should know, as I'm one of them.)
>
> Best,
> - Joe

Python can do the swap operation on mutable types, for example.

By-Value and By-Reference are not the only passing methods.  True or
False?



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