Pointer in C | Basic IT Topic

Pointer in C

Pointer in C

Pointer in C:-

A pointer in C is a variable which refers only address. (address is a location in memory).

Pointer is 4byte because an address is a 4 byte long.

Pointer cannot refers any address beyond 4GB of memory in GCC compiler.


It is used for dynamic memory allocation and array implementation.

Function pointer implementation.

Array implementation

Direct address and hardware address.

Random access or direct access address of memory variable.


Dangling pointer:-

If a pointer refers unauthenticated address in memory is called  dangling pointer.

#include <stdlib.h>

#include <stdio.h>

int main()


    int *p = (int *)malloc(sizeof(int));

    // ptr becomes a dangling pointer


p = NULL;


Wild pointer:-

If a pointer does not refer any address in memory called wild pointer.

#include <stdio.h>
int main()


    int *p; // wild pointer

    int x = 10;

    // p is not a wild pointer now

    p = &x;

    return 0;


Null pointer:-

When the pointer refers the starting address of the memory is zero address is called null pointer.


It represents the last node of a link list.

It represents the stack or queue is empty or not.

It represents heap memory is empty or not.

#include <stdio.h>

int main()


    // Null Pointer

    int * = NULL;


    printf("The value of pointer is %u", p);

    return 0;


D  reference:-

Doing write or read operation using pointer the concept is called D reference.

D reference of a dangling pointer and wild pointer became segmentation from.

Generic pointer:-

Pointer to void type is called generic pointer.

Generic pointer can refer any address but it cannot be difference

#include <stdio.h>



int x=10;

void *p=&x;




Generic pointer is suitable to refer incomplete types(the memory is allocated  by malloc and calloc )

It is suitable to refer VA-list (VA-list is used as the formal parameter of a function).

Near pointer:-

If a pointer refers address the same segment memory is called near pointer.

Far pointer:-

If a pointer refers address in other segments in memory is called far pointer.



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