What's the use of const here

Question

in

int salary() const { return mySalary; }

as far as I understand const is for this pointer, but I\'m not sure. Can any one tell me what is the us

Answer 1

It's a const member function. It's a contract that the function does not change the state of the instance.

more here: http://www.fredosaurus.com/notes-cpp/oop-memberfuncs/constmemberfuncs.html