pointer-memory addresses

[TerryK]

What address in memory wil be assigned to the following:

float *floatptr;

floatptr = 100;

floatptr = +- 8;

[Hammer]

#include <stdio.h>
int main(void)
{
	float *floatptr; 
	
	floatptr = 100; 
	printf("pointer address is %p\n", floatptr);
	floatptr = +- 8;
	printf("pointer address is %p\n", floatptr);
	return(0);
}

Output from compiler:

Borland C++ 5.5 for Win32 Copyright (c) 1993, 2000 Borland
E:\AAPgm\MyProg\C\junk\junk6.c:
Warning W8069 E:\AAPgm\MyProg\C\junk\junk6.c 6: Nonportable pointer conversion in function main
Warning W8069 E:\AAPgm\MyProg\C\junk\junk6.c 8: Nonportable pointer conversion in function main
Turbo Incremental Link 5.00 Copyright (c) 1997, 2000 Borland

Output from program when run:

E:\AAPgm\MyProg\C\junk>junk6
pointer address is 00000064
pointer address is FFFFFFF8

You don't assign hard coded values to pointer in this manner (with the exception of NULL).

[*]

> You don't assign hard coded values to pointer in this manner (with the exception of NULL).

Actually, that's not absolute. Obviously, there is a time and place to actually assign hard-coded values to a pointer. For example, if you are accessing a ROM address, or a known trap-address.

Normally, however, a pointer's value (it's contents) is established when you allocate memory to go with it (for example, when using malloc()).

Or, as Hammer stated, when you initialize the variable to a known, state, like nil.