Difference between static and constant function in C++
Static Function: It is a member function that is used to access only static data members. It cannot access non-static data members not even call non-static member functions. It can be called even if no objects of the class exist. It is also used to maintain a single copy of the class member function across different objects of the class.
Constant Function: It is a function that is generally declared as constant in the program. It also guarantees that it will not allow modifying objects or call any non-const member functions. It specifies that function is a read-only function and does not modify the object for which it is called.
Tabular Difference between static function and constant function:
|It is declared using the static keyword.||It is declared using the const keyword.|
|It does not allow variable or data members or functions to be modified again. Instead, it is allocated for a lifetime of the program.||It allows specifying whether a variable is modifiable or not.|
|It helps to call functions that using class without using objects.||It helps us to avoid modifying objects.|
|This function can only be called by static data members and static member functions.||This function can be called using any type of object.|
|It is useful to declare global data which should be updated while the program lives in memory, used to restrict access to functions, reuse the same function name in other files, etc.||It is useful with pointers or references passed to function, used to avoid accidental changes to object, can be called by any type of object, etc.|
|It is a member function that generally allows accessing function using class without using an instance of the class.||It is a member function that is generally declared as constant in the program.|