This will yield ABEntry objects with the values you expect, but it’s still not the best approach. The rules of C++(www.cppentry.com) stipulate that data members of an object are initialized before the body of a constructor is entered. Inside the ABEntry constructor, theName, theAddress, and thePhones aren’t being initialized, they’re being assigned. Initialization took place earlier — when their default constructors were automatically called prior to entering the body of the ABEntry constructor. This isn’t true for numTimesConsulted, because it’s a built-in type. For it, there’s no guarantee it was initialized at all prior to its assignment.

A better way to write the ABEntry constructor is to use the member initialization list instead of assignments:

ABEntry::ABEntry(const std::string& name, const std::string& address,  
                      const std::list<PhoneNumber>& phones)  
:theName(name),  
 theAddress(address),  // these are now all initializations  
 thePhones(phones),  
 numTimesConsulted(0)  
{}  // the ctor body is now empty 

This constructor yields the same end result as the one above, but it will often be more efficient. The assignment-based version first called default constructors to initialize theName, theAddress, and thePhones, then promptly assigned new values on top of the default-constructed ones. All the work performed in those default constructions was therefore wasted. The member initialization list approach avoids that problem, because the arguments in the initialization list are used as constructor arguments for the various data members. In this case, theName is copy-constructed from name, theAddress is copy-constructed from address, and thePhones is copy-constructed from phones. For most types, a single call to a copy constructor is more efficient — sometimes much more efficient — than a call to the default constructor followed by a call to the copy assignment operator.