[완료] C++ Primer 4쇄를 보면서, 클래스 타입에 대한 컨스트럭터를 이용한 초기화 란것이 대체 무엇인가요?

The declaration of myobj compiles without complaint. However, when we try to use myobj

Sales_item myobj(); // ok: but defines a function, not an object
if (myobj.same_isbn(Primer_3rd_ed)) // error: myobj is a function

the compiler complains that we cannot apply member access notation to a function! The problem is that our definition of myobj is interpreted by the compiler as a declaration of a function taking no parameters and returning an object of type Sales_itemhardly what we intended! The correct way to define an object using the default constructor is to leave off the trailing, empty parentheses:

// ok: defines a class object ...
Sales_item myobj;

On the other hand, this code is fine:

// ok: create an unnamed, empty Sales_itemand use to initialize myobj
Sales_item myobj = Sales_item();

Here we create and value-initialize a Sales_item object and to use it to initialize myobj. The compiler value-initializes a Sales_item by running its default constructor.