C++ Pointer Operator

In this chapter we are going to study C++ Pointer Operators. C++ provides two pointer operators one is value at operator or indirection operator and address operator.

C++ Pointer Operator

C++ Address of Operator (&)

1. The & is a unary operator means it requires only one operand.
2. The Address of Operator returns the memory address of its operand.
3. Address of operator has the same precedence and right-to-left associativity as that of other unary operators.
4. Symbol for the bitwise AND and the address of operator are the same but they don’t have any connection between them

C++ Program : Address of Operator

#include<iostream>
using namespace std;
int main()
{
   int num=10;
   cout << "Value of number   : " << num << endl;
   cout << "Address of number : " << &num << endl;
}

Output :

Value of number : 10
Address of number : 0xffad72dc

Summary

C++ Indirection Operator *

1. The Indirection operator * is a unary operator means it requires only one operand.
2. Indirection Operator (*) is the complement of Address of Operator (&).
3. Indirection Operator returns the value of the variable located at the address specified by its operand.

C++ Program : Indirection Operator

#include<iostream>
using namespace std;
int main()
{
   int num=10;
   int *ptr;
   ptr=&num;
   cout << " num = " << num << endl;
   cout << " &num = " << &num << endl;
   cout << " ptr = " << ptr << endl;
   cout<< " *ptr = " << *ptr << endl;
}

Output :

num = 10
&num = 0xffcc2bd8
ptr = 0xffcc2bd8
*ptr = 10

Calculations:

// Sample Code for Dereferencing of Pointer
*(ptr) = value at (ptr)
       = value at (0xffcc2bd8) 
       = 10
//Address in ptr is nothing but address of num

Summary

Though multiplication symbol and the “Indirection Operator” symbol are the same still they don’t have any relationship between each other.

Both & and * have a higher precedence than all other arithmetic operators except the unary minus/plus, with which they share equal precedence.