Question

For example:

object* pObject = nullptr;

OR:

object* pObject = 0;

Again, which one is better performance wise?

Answer 1

nullptr is of type std::nullptr_t and so the constructor be overloaded. This means the fact that it is null is encoded in the type, so it can be theoretically faster by avoiding a conditional.

Pointers obviously don’t have overloaded constructors so whether you use 0 or nullptr is irrelevant. Same machine code, same performance.

Anyway, go with nullptr when you want a null pointer. Be careful of 0 as it will call integer overloads rather than pointers.