C++ Class Methods

In C++, a method (member function) is a function declared within a class that operates on its objects. Member functions can access the class's private/protected data and define how objects behave.

A method can be defined directly inside the class body or declared inside the class and defined outside using the scope resolution operator (::).

If a method is defined inside the class, it is implicitly declared with the inline specifier. This enables placing the definition in headers without violating the One Definition Rule. Note that inline does not force inlining; the optimizer decides whether to inline the call.

For better organization, methods are often declared inside the class and defined outside using the scope resolution operator ::. The out-of-class definition must repeat the exact signature (including qualifiers like const, noexcept, reference qualifiers, etc.).

Member functions can take parameters and return values like free functions. Use const on methods that do not modify the object's state.

Inside a const member function, the implicit this pointer is const ClassName*, so you cannot modify non-mutable data members. You can provide both const and non-const overloads when appropriate.

Static member functions do not have a this pointer and cannot access non-static members unless given an object/reference. They are often used for utilities related to the class.