pointer to member function c++ code example

Example 1: Function pointer C++

void one() { cout << "One\n"; }
void two() { cout << "Two\n"; }


int main()
{
	void (*fptr)(); //Declare a function pointer to voids with no params

	fptr = &one; //fptr -> one
	*fptr(); //=> one()

	fptr = &two; //fptr -> two
	*fptr(); //=> two()

	return 0;
}

Example 2: calling by reference and pointers c++

#include <iostream>
using namespace std;

// Function prototype
void swap(int&, int&);

int main()
{
    int a = 1, b = 2;
    cout << "Before swapping" << endl;
    cout << "a = " << a << endl;
    cout << "b = " << b << endl;

    swap(a, b);

    cout << "\nAfter swapping" << endl;
    cout << "a = " << a << endl;
    cout << "b = " << b << endl;

    return 0;
}

void swap(int& n1, int& n2) {
    int temp;
    temp = n1;
    n1 = n2;
    n2 = temp;
}