Re: const int value changing....
- From: Christian Bau <christian.bau@xxxxxxxxxxxxxxxxxxxx>
- Date: Mon, 22 Aug 2005 23:54:24 +0100
In article <1124688926.558688.45670@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"shyju_kambi" <n.shyju@xxxxxxxxx> wrote:
> when a 'const int ' is declared, where is it been created(in RAM?)
>
> #include<stdio.h>
> int main()
> {
> const int i=10;
> const int *p;
> p=&i;
> *p=12;
> printf("\n %d %d",i,*p);
> return 0;
> }
>
> ---------------------------------------------------------
> the following program i tryied, still i was unable to change the value
> of a const.
>
> when a variable is declared, a ram location is allocated for it.
It seems you have a little knowledge how computers work. A little
knowledge can be very very dangerous. Forget about "ram locations".
Download a copy of the C Standard, or at least a copy of the last draft
of the C Standard, and use that as a reference. You won't find "ram
locations" mentioned there anywhere.
> then
> why i cant change the value of that variable using pointer?
>
> if the variable i've declared as a 'static int ' then using pointer i
> can change the value.
>
>
> plz give solutions
Solution? Don't do it.
In many cases, the compiler won't allow you to modify a const variable.
However, you can trick the compiler into allowing code that attempts to
modify such a const variable.
Any code that attempts to modify a const variable invokes UNDEFINED
BEHAVIOR. That means: Anything could happen. And that means _absolutely
anything_. If you modify a const variable, and as a result your harddisk
gets formatted, don't complain, it is your own fault. If it makes a
server crash and half a dozen people need a week to fix it, don't
complain, it is your fault.
(This will most likely not happen in a simple program that you write to
try out things. It will happen when you write a program that is used by
ten thousand customers, and then you are in trouble. )
.
- References:
- const int value changing....
- From: shyju_kambi
- const int value changing....
- Prev by Date: Re: how will u call this fn
- Next by Date: Re: c interview questions wiki
- Previous by thread: Re: const int value changing....
- Next by thread: LOGO Linked List Sort using pointer
- Index(es):
Relevant Pages
|
