have a C doubt ?

Question

is int *ptr = NULL ;
same as int *ptr = 0 ;

Answer 1

There is no nullptr type in C. nullptr is a C++ feature that was added to prevent you from calling the wrong overloaded function when one took an integer and the other a pointer argument.
A 0-as-null argument causes ambiguity, is it a null pointer or an integer? The nullptr cleared up that confusion by always calling the pointer function.

The second reason is that C++ doesn't type promote void pointers so the (void *)0 was not an option.

NIK

In C void pointers are automatically type promoted and there is no function overloading so NULL is fine. In C++ it's better to use nullptr due to the reasons above.

You should use NULL for pointers, 0 for integers and '\0' for characters by convention. It shows what variable type you're working with and it's less confusing.

Answer 2

With pointers you should use nullptr
int *ptr = nullptr;
You can also use 0 or NULL , but nullptr is for pointers and I won't be cause an error in some situations .

Answer 3

so they are the same but can have undefined behavior thats what u are saying ?