CODEWITHSUNDEEP
cpointersnull
Zephyr
Zephyr

Reputation: 1621

Null assignment

#include<stdio.h>
#include<conio.h>

void main()
{
    int *p=NULL;
    *p=30;
    printf("%d %p", *p,p);  //output:- 30 0000
}

p should be pointing to address 0 and I think there should be null assignment error. But how *p is giving output as 30? Is 30 stored in location 0000? According to me 0th address should not be assigned to any variable.

Upvotes: 1

Views: 110

Answers (1)

P.P
P.P

Reputation: 121357

[..] I think there should be null assignment error.

C staandard doesn't provide any such guarantees.

Dereferencing a null pointer is undefined behaviour. So, there's no point in reasoning about why it prints 30. Btw, you should cast the pointer argument to void* to print it:

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

Upvotes: 1

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