Prerequisite: Pointers in C++

A pointer variable is a variable that stores the address of another variable or in other a pointer variable points to the variable whose address is stored inside it.

Syntax:

int *pointer_name; 

There are mainly two types of Pointer operators mainly used:

• Address of operator (&)
• The indirection operator/Dereference operator (*)

1. Address-of operator (&)

The Address-of operator (&) is a unary operator that returns the memory address of its operand which means it stores the address of the variable, which depicts that we are only storing the address not the numerical value of the operand. It is spelled as the address of the variable.

Syntax: 

gfg = &x; // the variable gfg stores the address of the variable x.

Example:

// C++ Program to demonstrate
// the use of Address-of operator (&)
#include <iostream>
using namespace std;

int main()
{

    int x = 20;

    // Pointer pointing towards x
    int* ptr = &x;

    cout << "The address of the variable x is :- " << ptr;
    return 0;
}

// C++ Program to demonstrate

// the use of Address-of operator (&)

#include <iostream>

using namespace std;

​

int main()

{

​

    int x = 20;

​

    // Pointer pointing towards x

    int* ptr = &x;

​

    cout << "The address of the variable x is :- " << ptr;

    return 0;

}

The address of the variable x is :- 0x7fff412f512c

2. The indirection operator/Dereference operator (*)

The indirection/ dereference operator is a unary operator that returns the value of the variable present at the given address. It is completely opposite to the address-of operator. It is spelled as a value pointed at the address.

Example:

// C++ Program  to Demonstrate
// the indirection/Dereference operator
#include <bits/stdc++.h>
using namespace std;

int main()
{

    int self_paced = 3899;
    int* price;

    // Pointer storing address of self_paced
    price = &self_paced;

    cout
        << "The value stored at the variable price is Rs : "
        << (*price);

    return 0;
}

// C++ Program  to Demonstrate

// the indirection/Dereference operator

#include <bits/stdc++.h>

using namespace std;

​

int main()

{

​

    int self_paced = 3899;

    int* price;

​

    // Pointer storing address of self_paced

    price = &self_paced;

​

    cout

        << "The value stored at the variable price is Rs : "

        << (*price);

​

    return 0;

}

The value stored at the variable price is Rs : 3899