What is the purpose of a destructor?

Which STL class is the best fit for implementing a phonebook? Suppose each entry contains a name and a phone number, with no duplicates, and you want to have lookup by name.

What is the main difference between these two Functions? std::mutex::lock() Std::mutex::try_lock()

What is one benefit of declaring the parameter as a const reference instead of declaring it as a regular object? int median(const my_array& a)

What is an include guard?

What is the purpose of this line in a header file? #pragma once

In C++, a comment can only be specified with a leading //.

What is the difference between a class and a struct

What does the sizeof(arg) operator do?

Classes can contain static member variables which are global to the class and...

Which is(are) an example(s) of valid C++ function prototype(s)?