Bill wrote:
Mark Lawrence wrote:
On 22/09/2017 08:01, Bill wrote:
Steve D'Aprano wrote:
On Fri, 22 Sep 2017 02:57 pm, Bill wrote:
I find Python to be more more
like Java, with regard to "passing objects by reference".
Which is not a surprise, since both Python and Java use the same
value passing
style: pass by object reference, or pass by sharing if you prefer.
Java people don't call it that. They call it pass by value, and
categorically
deny that it is pass by reference. (They're right about the second
point.)
I figure that, internally, an address, a pointer, is being passed by
value to implement pass by reference. Why do you say "they are
right" above? Are you saying it's not pass by reference?
Please see
http://jeffknupp.com/blog/2012/11/13/is-python-callbyvalue-or-callbyreference-neither/
and http://effbot.org/zone/call-by-object.htm
I would would agree with the description provided for the C++ example
provided
string some_guy = "fred";
is replaced by
char* some_guy="fred";
On second thought, so that the description is correct (matches the
semantics), replace it by
char some_guy[10]="fred";
But then you need to use std::strcpy to reassign some_guy
to "george".
To see that this is correct, note the some_guy may subsequently be
assigned to a character string much longer then "fred". An additional
note: A character string literal, like "cat", never occurs more than
once in compiled C++ program unit. This also shows that the provided
description can't be completely correct. One last thing,
string some_guy = "fred"
is really the same thing as
string some_guy("fred");
and both equivalently call the string constructor.
The data type of "fred" is const char*, not (class) string.
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