how to use pointes
#include <iostream>
using namespace std;
int main () {
int firstvalue = 5, secondvalue = 15;
//declaring pointers
int *p1, *p2;
p1 = &firstvalue; // p1 = address of firstvalue
p2 = &secondvalue; // p2 = address of secondvalue
*p1 = 40; // value pointed to by p1 = 10;
*p2 = *p1; // value pointed to by p2 = value pointed to by p1
p1 = p2; // p1 = p2 (value of pointer is copied)
*p1 = 20; // value pointed to by p1 = 20;
//p1 got replaced with the address of p2;
cout << "firstvalue is " << firstvalue << '\n';
cout << "secondvalue is " << secondvalue << '\n';
return 0;
}