Constant object : For example, if you set a class Demo, then const Demo Obj;//Defines that Obj is a constant object. In this way, the value of this object will not be changed
Constant member function :
1. Definition
The const keyword can be added after the member function description of the class, then the member function is a constant member function.
2. Declaration
class Sample
{
public:
int value;
void GetValue() const;
void func(){
};
Sample(){
}
};
A const member function should not modify the object it acts on during execution. Therefore, the value of member variables cannot be modified in a constant member function (except for static member variables), nor can the same non-constant member function be called (except for static member functions).
Constant objects, and references or pointers to constant objects can only call constant member functions.