Void Pointer in C++

1. Implement the void* Pointer in C++
2. Size of the void* Pointer in C++

This article will discuss the uses of void* pointers in C++. An example code is also provided to demonstrate its implementation.

Implement the void* Pointer in C++

We have studied that the pointer should be of the same data type to which it is pointing, as specified in the pointer declaration. If we declare a float pointer, it cannot point to any other data type such as int, long, or string; it can only point to a float type variable.

C/C++ has developed a solution to overcome this problem - the void* pointer. A void* pointer is a general-purpose pointer that can point to any data type without any static pointer definition.

You can assign the address of any data type to a void* pointer. Similarly, the void* pointer can be assigned to any data type of pointers without explicitly typecasting them.

Syntax:

void *pointerName;
void *ptr;

There are two main disadvantages of using void* pointers in C++:

1. Due to the concrete size, performing pointer arithmetic is not possible with the void* pointer in C++.
2. You cannot dereference a void* pointer.

Size of the void* Pointer in C++

The size of the void* pointer is similar to the size of the pointer of the character type in C++. The pointer stores the memory address that points to some data in the program.

This pointer in C++ depends on your computer platform. On a 32-bit platform, you need 4 bytes or 32 bits to store the memory address data.

The sizeof() function can identify the size of the pointer.

Syntax:

void *ptr = NULL;  // void pointer
sizeof(ptr);

Example code:

#include
#include

using namespace std;

int main() {
  void *ptr = NULL;  // void pointer
  int *p = NULL;     // integer pointer
  char *cp = NULL;   // character pointer
  float *fp = NULL;  // float pointer

  // size of pointers
  cout

Reason to Use void* Pointers in C++ Programs

We use the void* pointer in C++ to overcome the issues of assigning separate values to different data types in a program. The void* pointer in C++ can point to any data type and typecast that data type without explicitly typecasting.

It does not have any return value. A void* pointer can point to an int, float, or char and typecasts to that specific data type.

It helps developers in writing code and reducing the complications of a program.