When we declare a pointer variable like so, its content is not intialized:
In other words, it contains an address of “somewhere”, which is of course not a valid location. This is dangerous! We need to initialize a pointer by assigning it a valid address.
But suppose we don’t know where we are pointing to, we can use a null pointer.
nullptr is a new keyword introduced in C++11. It provides a typesafe pointer value representing an empty pointer.
We can use
nullptr like so:
int* ptr = nullptr;
Note: In older C/C++ code,
NULL was used for this purpose.
nullptr is meant as a modern replacement to
Change the declaration of
ptr and initialize it to