Callbacks In C

Callbacks In C

In C programming, callbacks are a powerful technique. They let you pass functions as arguments to other functions, which can then use those functions at specific times or when certain events occur. This flexibility allows you to create adaptable software that can respond to different situations, user actions, and asynchronous tasks. Learning how to use callbacks in C is essential for building modular, flexible, and event-driven software. In this discussion, we’ll explore the world of callbacks in C and how they can be useful in various programming situations.

What is Callbacks In C

A callback is a programming concept where a piece of executable code, often in the form of a function or method, is passed as an argument to another piece of code. The receiving code is designed to call back or execute this argument at a specific point or under certain conditions. In simpler terms, when you pass a reference to a function as an argument to another function with the intention of having it invoked later, that function becomes known as a callback function.

Callbacks are a powerful tool in programming and are commonly used for various purposes, such as event handling, asynchronous programming, and customizing behavior in libraries or frameworks. In C, a callback function is a function that gets called through a function pointer.

Example to illustrate Callbacks

// A simple C program to demonstrate callback
#include <stdio.h>
 
void A(){ 
  printf("I am function A\n");
}
 
// callback function
void B(void (*ptr)())
{
    (*ptr)(); // callback to A
}
 
int main()
{
    void (*ptr)() = &A;
 
    // calling function B and passing
    // address of the function A as argument
    B(ptr);
 
    return 0;
}

Output

I am function A

FAQ- Callbacks In C