why use pointer variables c++ code example

Example 1: pionter in c++

#include <iostream>
using namespace std;
int main(){
   //Pointer declaration
   int *p, var=101;
 
   //Assignment
   p = &var;

   cout<<"Address of var: "<<&var<<endl;
   cout<<"Address of var: "<<p<<endl;
   cout<<"Address of p: "<<&p<<endl;
   cout<<"Value of var: "<<*p;
   return 0;
}

Example 2: c++ pointers

#include <iostream>

using namespace std;

int main () {
   int  var = 20;   // actual variable declaration.
   int  *ip;        // pointer variable 

   ip = &var;       // store address of var in pointer variable

   cout << "Value of var variable: "; 
   cout << var << endl; //Prints "20"

   // print the address stored in ip pointer variable
   cout << "Address stored in ip variable: ";
   cout << ip << endl; //Prints "b7f8yufs78fds"

   // access the value at the address available in pointer
   cout << "Value of *ip variable: ";
   cout << *ip << endl; //Prints "20"

   return 0;
}