What is the purpose of a function pointer in C++?

A function pointer in C++ is a pointer variable that points to a function. Its purpose is to allow functions to be passed as parameters to other functions, dynamically choose to call different functions, or alter the behavior of a function at runtime as needed.

Function pointers can be used to implement callback functions, where a function’s pointer is passed as a parameter to another function, which then calls the passed function based on certain conditions to achieve different functionalities.

Function pointers can also be used to encapsulate and abstract functions, enhancing the flexibility and reusability of code. By passing a function pointer as a parameter to a generic function, the specific function to be called can be determined at runtime, enabling dynamic function calls.

In addition, function pointers can also be used to achieve dynamic loading of functions and runtime decision-making. By pointing function pointers to different functions, you can choose the appropriate function to call at runtime based on different situations, thus achieving program flexibility and scalability.