Pointer in C++

Pointer in C++

Pointer

To create linked list in C/C++ we must have a clear understanding about pointer. Now I will explain in brief what is pointer and how it works.

A pointer is a variable that contains the address of a variable. Using pointer we can pass argument to the functions. Generally we pass them by value as a copy. So we cannot change them. But if we pass argument using pointer, we can modify them. To understand about pointers, we must know how computer store variable and its value. Now, I will show it here in a very simple way.

Let us imagine that a computer memory is a long array and every array location has a distinct memory location.

int a = 10 // initialize variable a

It is like a house which has an address and this house has only one room. So address of house like this

• Name of the house: a
• Name of the person/value who live here is: 50
• House Number: 4010

If we want to change the person/value of this house, the conventional way is, type this code line

a = 100 // new initialization

But using pointer we can directly go to the memory location of 'a' and change the person/value of this house without disturbing a. This is the main point about pointer. Use pointer like below code;

int *b;    // declare pointer b

Here We transfer the memory location of a to b.

b = &a; // the unary operator & gives the address of an object

In above Images Integer pointer b store the address of the integer variable a. Now, we can change the value of a without accessing a.

*b = 20;  // change the value of 'a' using pointer ‘b’
 cout<

#include <iostream.h>
using namespace std;
 
int main()
{
   int a = 10;       // initialize integer variable a
   cout<<"The value of 'a': "<

The value of 'a': 10
The value of 'a' using *b: 20