C Programming

Pointer vs Handles in C

When it comes to programming in C, pointers and handles are two essential concepts in managing memory and data structures but they are often confused or used interchangeably. In C programming, a handle is a reference to an object in memory, whereas a pointer is a variable that is assigned the address of another variable. Both are used to reference and manipulate memory addresses in different ways.

In this article, we will see whether these terms are used to convey separate things.

What Is a Pointer in C?

Pointers store the memory address of any other variable. A pointer is made by defining a variable of the pointer type and using the ‘&‘ operator to assign it the address of another variable. Pointers are used to indirectly access and modify data through memory addresses. Pointers can be used to transfer information between functions and allocate memory on-the-fly.

#include <stdio.h>
int main()
{
   int* point_c, c;

   c = 10;
   printf("Address of c: %p\n", &c);
   printf("Value of c: %d\n\n", c);

   point_c = &c;
   printf("Address of pointer c: %p\n", point_c);
   printf("Content of pointer c: %d\n\n", *point_c);

   c = 39;
   printf("Address of pointer c: %p\n", point_c);
   printf("Content of pointer c: %d\n\n", *point_c);

   *point_c = 5;
   printf("Address of c: %p\n", &c);
   printf("Value of c: %d\n\n", c);
   return 0;
}

In the above code, a pointer variable point_c of type int and a normal integer variable c, and c is initialized to 10 and the address of c is assigned to the pointer point_c. After that, the value of c is changed to 39, but the point_c is then assigned a different value which is 5, so when the value of c is printed, it changes the value at the memory location pointed by the point_c to 5.

Output

What Are Handles in C?

Handles are generic data structures that store references to dynamically allocated memory. Handles are used to abstract and manage resources in C by providing a level of indirection between the application and the resource. A handle is created by allocating memory for the resource and returning a pointer to the allocated memory. Strings and arrays are examples of complicated data structures that may be managed via handles.

Difference between Pointers and Handles in C

Here are some of the key differences between pointers and handles in C.

1: Direct Reference to Memory Location

One of the main differences between pointers and handles is that pointers directly reference a memory location, while handles provide an abstraction of a resource. Pointers are low-level constructs that expose the details of memory management, while handles are high-level constructs that hide the details of resource management. Pointers are more suitable for low-level programming tasks such as system programming, while handles are more suited for application-level programming tasks such as GUI programming.

2: Safety

Memory addresses can be accessed directly via pointers. This means that data can be stored and accessed more efficiently, especially with large data sets. Pointers also provide flexibility in programming, as they can be used in a wide variety of applications. But in this case, handles have a plus point in safety, as they ensure that the program does not directly access memory locations.

3: Efficiency

Handles can be less efficient than pointers, as they require additional memory and processing power to manage. They can also be limited by the programming language, as not all languages support handles.

4: Memory Management Behavior

Pointers require manual memory management using functions such as malloc() and free(). Pointers can be dangerous when they are not managed properly, resulting in memory leaks, invalid memory references, and segmentation faults. Handles, on the other hand, provide automatic memory management using functions such as reference counting or garbage collection. Handles are more robust and safer, ensuring that resources are always correctly managed.

Conclusion

Pointers and handles are two essential concepts in C programming that serve different purposes. Pointers are low-level constructs that directly reference memory locations, while handles provide an abstraction of a resource. Pointers require manual memory management, while handles provide automatic memory management. Pointers are more suitable for low-level system programming tasks, while handles are more suited for application-level programming tasks. When used appropriately, both pointers and handles are effective in C programming.

About the author

Hiba Shafqat

I am a Computer Science student and a committed technical writer by choice. It is a great pleasure to share my knowledge with the world in which I have academic expertise.