What is Pointer in C ?

webmaster — Mon, 03 Oct 2022 06:33:50 +0000

For storing the address of another variable pointers can be used.
Variables of type int,char, array, function or any other pointer can be of type pointer.
Architecture of a pointer determines the size of the pointer.
Size of the pointer depends on the architecture.
In 32 bit the size of the pointer is 2 byte.
Using pointer some of programming tasks in C can be easily done.

Declaring a pointer

The pointer in c language can be declared using * (asterisk symbol). It is also known as indirection pointer used to dereference a pointer.

int *a; //pointer to int  
char *c;//pointer to char

Pointer Example:

An example of using pointers to print the address and value is given below.

Pointer to array

int arr[10];  
int *p[10]=&arr;

Pointer to a function

void show (int);  
void(*p)(int) = &display;

Pointer to Structure

struct st {  

   int i;  

    float f;  

}ref;  

struct st *p = &ref;

Advantages of Pointer

Pointer reduces the code and improves the performance.
It is used to retrieving strings, trees, etc., and used with arrays, structures, and functions.
We can return multiple values from a function using the pointer.
It makes you able to access any memory location in the computer’s memory.

Usage of pointer

There are many applications of pointers in c language.

Dynamic memory allocation

In C language, we can dynamically allocate memory using malloc() and calloc() functions where the pointer is used.

Arrays, Functions, and Structures

Pointers in c language are widely used in arrays, functions, and structures.
It reduces the code and improves the performance.

What is Pointers in C++ ?

webmaster — Fri, 19 Aug 2022 09:41:33 +0000

Pointers are symbolic representation of addresses and it enables a program to simulate call-by-reference as well as to create and manipulate dynamic data structures.
It defines a pointer variable and its general declaration in C/C++ has the format.
Using unary operator (&) assigning the address of a variable to a pointer which returns the address of that variable.
Using unary operator (*) accessing the value stored in the address which returns the value of the variable located at the address specified by its operand.
When we increment a pointer, we increase the pointer by the size of data type to which it points, this is the reason data type to a pointer is knows how many bytes the data is stored inside.

Syntax

datatype *var_name; 
int *ptr;

Sample Code

#include 
using namespace std;
int main() {
	int  x = 27;  
	int  *ip;        
	ip = &x;       
	cout << "Value of x is : ";
	cout << x << endl;
	cout << "Value of ip is : ";
	cout << ip<< endl;
	cout << "Value of *ip is : ";
	cout << *ip << endl;
	return 0;
}

c++ pointers - Wikitechy