Doubt in pointer.

Hello All,
I have small doubt in pointer, doubt as follows:-

Code:

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int a;
int *ptr;
ptr = &a;
printf("%d", &a);
printf("%d", ptr);

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i have check in my VC++ compiler output is 1245052 1245052.

Now if i modify above code as follows:

Code:

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int a;
int *ptr;
ptr = 1245052;
printf("%d", ptr);

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Above code can't compile why?even though i am applying valide address of a.

Thanks in advance
Shwetha

1. to print address you should use

printf("%p", (void*)ptr);

2. your integer representation of the address could be not accurate
3. address value could change - so it not wise to set it hardcoded
4. if you really need it - you need a cast to the correct type

Quote:

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ptr = 1245052;

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in this regard i've also a doubt can we assign any constant value to a pointer.

Quote:

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Originally Posted by BEN10

in this regard i've also a doubt can we assign any constant value to a pointer.

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of course we can, pointer is just variable

problems begin when you try to dereference such address in case your constant chooses some value not availble to the program

Quote:

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Originally Posted by BEN10

in this regard i've also a doubt can we assign any constant value to a pointer.

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No it is not possible to assign constant value to pointer.

Code:

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int *ptr = 10  Will not work. since 10 is not associated with address.

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pointer is not just variable it is variable it can only hold address of another variable.

Quote:

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Originally Posted by shwetha_siddu

No it is not possible to assign constant value to pointer.

Code:

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int *ptr = 10  Will not work. since 10 is not associated with address.

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pointer is not just variable it is variable it can only hold address of another variable.

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you clearly do not know what you are talking about

Code:

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int main()
{
        int *p = (int*)10;
        return 0;
}

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works fine