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-   -   Why pointer cant have only value? (http://www.go4expert.com/forums/pointer-value-t8202/)

Why pointer cant have only value?

This is very simple question!!! Give me excat reason???

Example: Why it is wrong....
int main()
{
int * ptr;
*ptr=10;
return 0;
}

 shabbir 11Jan2008 19:22

Re: Why pointer cant have only value?

First you submitted your query as article and I have moved to the forum for discussion and next thing is your query and I don't see anything wrong there?

 Salem 11Jan2008 19:31

Re: Why pointer cant have only value?

It's wrong because you did this
*ptr = 10;
before you did this
ptr = somewhere;

You can't just declare a pointer and magically hope it points to somewhere useful. You have to do it yourself. Chaos and madness result if you don't.

int a;
ptr = &a;
Gets you a pointer to ONE integer

int a[10];
ptr = a;
Gets you a pointer to TEN integers

ptr = malloc( sizeof(*ptr) * 10 );
This too is a pointer to 10 integers. But at some point, you need to do
free( ptr );

Re: Why pointer cant have only value?

That's fine . I did'nt mean that.
Fetaures should be as ...

2. Pointer Keeping Only Values
3. Both

1 & 2 approximately same. But why 2 is not supported??

Re: Why pointer cant have only value?

dont tell me story of pointer that Pointer is made for only keeping some address . This is known by all.

 shabbir 11Jan2008 21:05

Re: Why pointer cant have only value?

Quote:
 Originally Posted by asadullah.ansari dont tell me story of pointer that Pointer is made for only keeping some address . This is known by all.
Its not meant to. Some things have some responsibility and so is the case with pointer.

 Salem 12Jan2008 14:29

Re: Why pointer cant have only value?

In that case, I've no idea what your question is.

 technosavvy 14Jan2008 15:41

Re: Why pointer cant have only value?

friend if pointer will only have values then what do you want to do with the variables !!

Code:

`int var;`
var can have values...

if pointer will only have values then what is the use of pointers...

Re: Why pointer cant have only value?

Quote:
 Originally Posted by technosavvy friend if pointer will only have values then what do you want to do with the variables !! Code: `int var;` var can have values... if pointer will only have values then what is the use of pointers...

I wanna use like this manner....

Code:

```int main() {   int *p,x=23;   *p=10;   //Some operation like simple variables   ......   ......   printf("%d", *p);   //After some Instant     p=&x;     // Some operation like pointer features As popular)     ......     ......     printf("%d", *p);    return 0; }```

 Salem 16Jan2008 13:28

Re: Why pointer cant have only value?

Sure, there's no problem with reassigning the pointer to point somewhere else, with p = &x;

The real problem with your code is that at *p = 10, your pointer is UNINITIALISED. That means the code is broken.

Try
Code:

```int *p; int old, new; p = &old; *p = 10; ... p = &new; *p = 20;```
Remember, before you do *p = something;, you need a p = somewhere; statement before it, otherwise you've no idea what's happened.

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