CPP Memory Management & Pointers 2

Question 1

What is a dangling pointer in C++?

Accepted Answer

A pointer that points to memory that has been freed or gone out of scope

Answer

A dangling pointer refers to memory that has already been deallocated or is no longer valid, leading to undefined behavior if dereferenced.

Question 2

Which smart pointer transfers ownership when assigned to another smart pointer of the same type?

Accepted Answer

std::unique_ptr

Answer

std::unique_ptr uses move semantics, so assigning it to another unique_ptr transfers ownership and sets the source to nullptr.

Question 3

What does the placement new operator do in C++?

Accepted Answer

Constructs an object at a pre-allocated memory address

Answer

Placement new constructs an object at a specific, pre-allocated memory location without performing any additional allocation.

Question 4

What is the purpose of std::allocator in C++?

Accepted Answer

To provide a customizable memory allocation strategy for containers

Answer

std::allocator is the default allocator used by STL containers, providing a customizable interface for memory allocation and deallocation.

Question 5

What happens when you delete a pointer that was not allocated with new?

Accepted Answer

It is undefined behavior

Answer

Deleting a pointer that wasn't allocated with new is undefined behavior and can corrupt the heap or crash the program.

(CPP) C++ Programming Professional Certificate Practice Test