Pointing at a place

Is certainly possible. You want to use great care. Rarely would you need to point a variable at a specific location. If, however, you have a memory-mapped timecard, you might might have a routine that sets a pointer to the starting address:
volatile clock_t* clockPtr = SomeFancyLibraryCall();
It is unlikely that you would want to increment such a pointer by one byte.

If, however, you have a pointer to an array of char:
char* text = "How are you?";
char* myPtr = test;
cout << *myPtr
woud give you 't'.
Then myPtr++ and cout << *myPtr
would give you 'e'.

add one hexa value to the value of the pointer and display it ...

it's very easy to force a variable to such location, just assigne to the pointer the location, but this is not safe at all ... how can u know if this location exists in the target computer memory ? and how can u know if it's a free non-protected location ? I recommend to let the OS select this location for you better unless you want to build an OS yourself ..

Also, by the way,
word alignment is very important for most (all?) computers. A float or double, for instance, must begin on a (memory location) mod 4 boundary for 32-bit computers.
If you have a float point to byte x in memory, changing the pointer to x+1 and using it will result in a segmentation fault.
John

Test it under visual C++ and you'll see it yourself.

Thanks for the responses guys. I know it is not recommended that I only increment by one byte. I am using this code in order to try and figure it out and see what happens to the memory...this is an experiment of sorts.

#include <iostream>
#include <string>
#include <iomanip>

using namespace std;

long double a, b, c;
long double *pa = &a;
long double *pb = &b;
long double *pc = &c;

void out (string title)
{
cout<< endl<<title<<endl;
setprecision(12);
cout << "a b c = " << a << " " << b << " " << c <<endl;
cout << "&a &b &c = " << &a << " " << &b << " " << &c <<endl;
cout << "*pa *pb *pc = "<< *pa << " " << *pb << " " << *pc <<endl;
cout << "a b c = " << a << " " << b << " " << c <<endl;
}
int main()
{

a = 2;
b = 3;
c = 4;

out("Test");

&pa = 0x445011;
&pb = 0x445019;
&pc = 0x445021;
out("Test");

system("PAUSE");
return EXIT_SUCCESS;
}

Thanks again

no i am getting errors on those three lines as follows
H:\pointer test.cpp non-lvalue in assignment

Amahdy: Visual C++ 6.0 is indeed very buggy in this respect (is this the version you meant?). When you have a char * pointer, or in fact any other pointer, there's a simple and consistent rule about which deletion should be used: check how the pointer was allocated. Was it allocated using new or new[]? If it's the former, you must use delete. If it's the latter, use delete[]. Yes, you may need to use delete in some cases. For example:
char * p = new char; //one byte, not an array
delete p;
p = new char [2]; //now an array, and yes, you can use the same p
delete[] p; //correct

It took me awhile but I think I understand now what you really meant: allocating an object on a predetermined memory address. Yes, you can do that using placement new. http://www.dev-archive.com/dev-archive/LegacyLink/9485