How do pointers relate to references?

Pointers are generally used to store the memory address of another variable, while references are just another name of the existing variable.

Can we have a reference to a pointer?

References to pointers are declared in the same way as references to objects.

Can a reference be Null?

No, references can’t be Null.

Table of contents

Introduction

Pointers

2.1.

C++ code for pointers

Reference

3.1.

C++ code for reference

Difference between pointers and reference

Frequently Asked Questions

Conclusion

Last Updated: Mar 27, 2024

Easy

Difference between Pointers and References

Author Sacksham Sharma

Introduction

C++ reference and pointer appear to be similar. However, there are a few variations that exist among them. A reference is a variable, and we can call it another name of that existing variable, even as the pointer is a variable that stores the memory address of that existing variable.

Also see, Literals in C, Fibonacci Series in C++

Pointers

A pointer is a variable that consists of the address of another variable.
It may be dereferenced with the assistance of the (*) operator.
By using the *operator, we can access that memory location where the pointer points.

C++ code for pointers

// C++ program to demonstrate use of * for pointers in C++
#include <iostream>
using namespace std;
 
int main()
{
    // variable declared and value assigned
    int v = 10;
 
    // A pointer variable p that holds the address of v.
    int *p = &v;
 
    // This line prints value at address stored in p.
    // Value stored is value of variable "v"
    cout << "Value of v = "<< *p << endl;
 
    //Address may be different for different machines
    cout << "Address of v = " <<  p << endl;
 
    // Value at address is now 20
    *p = 20; 
 
    // This prints 20
    cout << "After doing *p = 20, *p is "<< *p << endl;
 
    return 0;
}

Output:

Value of v = 10
Address of v = 0x7ffe6ea2b294
After doing *p = 20, *p is 20

Reference

A reference is a variable like &x =y.
this is called some other name for an already present variable. The reference of a variable is created via way of means of storing the address of another variable.
A reference variable may be taken into consideration as a regular pointer with automated indirection. Here, automated indirection means that the compiler auto applies the indirection operator (*).

C++ code for reference

#include<iostream>
using namespace std;
  
int main()
{
    
  // declaring and assigning value to variable
  int var = 10;
  
  // ref is a reference to x.
  int& ref = var;
  
  // Value of x is now changed to 20
  ref = 20;
  cout << "var = " << var << endl ;
  
  // Value of x is now changed to 30
  var = 30;
  cout << "ref = " << ref << endl ;
  
  return 0;
}

Output:

var = 20
ref = 30

You practice by yourself with the help of online c++ compiler.