Posted by Summercool on 09/28/07 15:43

sorry, the message was accidentally posted before it was complete:

First of all, I think in the very traditional and basic form of
"reference", it means "pointers".

So that's why in C,

when you say

int *ip;

ip is a pointer or "reference" to an integer. and that's why when you
use it to get back the integer, you need to do *ip and that's called
"dereference".

So in C++, it seems that there is a different kind of reference, and
that's like an alias type of reference? So in C++, Java, and PHP, you
can have

a = 10; b = 20;
int i = a;
int &j = i;
printf "%d", j; and you get 10?
j = b;
printf "%d %d", i, j; and both are 20 now?

that's different from the traditional pointer reference

a = 10; b = 20;
int *ip = &a; // ip pointers to an integer
int *jp = ip; // jp pointers to the same integer
printf "%d", *jp; // print 10
jp = &b; // now jp pointer to a different integer
printf "%d %d", *ip, *jp; // now it prints 10 and 20


the first behavior is the same as PHP's
$a =& $b

the second behavior is the same as PHP5's object assignment:
$obj1 = $obj2

so it seems like both are called a reference?

Isn't there standard names for their difference? The first one is
more like "an alias reference". The second one is like "a pointer
reference". I think calling them the same as "reference" is very
dangerous as they mean different things and behave differently.


some discussions:
http://en.wikipedia.org/wiki/C%2B%2B_reference
http://en.wikipedia.org/wiki/Reference_%28computer_science%29

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