Like pointers in C ( *int , *char ) we can use pointers to a function .

Here's a sample of Function Pointer ::

#include "iostream"
void Sample(){
    std::cout << " This is sample function call ." << std::endl;
};
int main(){
    auto function = Sample;

    function();    
    function();    
};

We can use it as ::

#include "iostream"

void Sample(){
    std::cout << " This is sample function call ." << std::endl;
};

int main(){

    void(*function)();

    function = Sample;

    function();    
    function();
};

Using typedef in function pointers ::

#include "iostream"

void Sample(){
    std::cout << " This is sample function call ." << std::endl;
};

int main(){
    typedef void(*Function)();

    Function function = Sample;

    function();    
    function();
};

Passing a Function as a Parameter to another function to call it ::

#include "iostream"
#include "vector"

void PrintValue(int value){
    std::cout << "The Value got is : " << value << std::endl;
};

void ForEach(const std::vector<int>& values , void(*function)(int)){
    for(auto i : values){
        function(i);
    };    
};

int main(){
    std::vector<int> sample_vector = {1,2,4,3,5,7};
    ForEach(sample_vector,PrintValue);
};