Returned Pointer gives different address?!?!

[Tset Tsyung]

Hi all!

I apologise if this is a wall of text...

I have been going through the "C++ for dummies book". On page 125 (should any of you have it) it states that in a function you can use the heap memory to create a portion of memory for, say, a double. And that once you leave the function, even though the variabl is out of scope, the heap will retain the portion for the double.

However I am using pointers (as per the example on the page) to check this. I am printing to the console the address from the pointer which is looking at the new heap block. I am then returning that pointer to main, where I am then again printing the address to the console.

The problem is that both pointers are looking at different areas of memory. I was under the impression that the heap keeps the block and therefore both the original (dppointer) and the returned pointer (dpmydouble) would be looking at that same block!

What am I doing wrong?

P.S. I'm using the version of bundled Code::Blocks and GNU GCC compiler that came with the book.

To assist with this conundrum, here is my code and ouputs.:


CODE:
// MorePointerTesting
// This program is to test the use of 'new' and 'delete'

#include <iostream>
#include <cstdlib>

using namespace std;

double* fndoublereturn (void);

int main()
{
double* dpmydouble = fndoublereturn();

cout << "dpmydouble points to: " << dpmydouble
<< endl;

delete dpmydouble;
dpmydouble = 0;

return 0;
}
//-----------------------------------------------//
// Functions Below //
//-----------------------------------------------//
double* fndoublereturn (void)
{
double* dppointer = new double;
cout << "Debug from fndoublereturn is: " << &dppointer << endl;
return dppointer;
}


OUTPUT (Average):
Debug from fndoublereturn is: 0x22feec
dpmydouble points to: 0x360fd0

Process returned 0 (0x0) execution time : 0.093 s
Press any key to continue.

[kbw]

&dppointer is the address of the pointer.
dppointer is the value pointed to. You should be using this in your code.

[Tset Tsyung]

Oh my word... that is totally right!

Thank you so much! That ACTUALLY helps make it all clearer - Thanks again!

P.S. for anyone reaing this thread removing the '&' from in front of dppointer in function fndoublereturn() means both pointers return the same address!

Thanks again kbw!