C + + Primer 12 Chapter Class

1. About const objects of a class

Const objects can only invoke member functions declared as const, which is also discussed in this CSDN blog .

The reason is because

The const object A calls the non-const function f, f because there is no const constraint to modify the members within the A object, does that violate the original intent of the a declaration const?

Conversely, it is possible to call a const function on a non-const object.

2. Const-based overloading

The member functions of the Const modifier can be described in this Sina blog!

A member function can be overloaded based on whether the member function is const;

A function can be overloaded based on whether a pointer parameter is const.

eg

void Isnumber (const int&);

void Isnumber (int &);

void Isnumber (const int &) const;

3. Other uses of const

You can see this blog post

C + + Primer 12 Chapter Class