Open In App
Related Articles

Callbacks in C

Improve Article
Save Article
Like Article

A callback is any executable code that is passed as an argument to another code, which is expected to call back (execute) the argument at a given time. In simple language, If a reference of a function is passed to another function as an argument to call it, then it will be called a Callback function.

In C, a callback function is a function that is called through a function pointer.

Below is a simple example in C to illustrate the above definition to make it more clear.


// 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
    return 0;


I am function A

In C++ STL, functors are also used for this purpose.

If you like GeeksforGeeks and would like to contribute, you can also write an article using or mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Whether you're preparing for your first job interview or aiming to upskill in this ever-evolving tech landscape, GeeksforGeeks Courses are your key to success. We provide top-quality content at affordable prices, all geared towards accelerating your growth in a time-bound manner. Join the millions we've already empowered, and we're here to do the same for you. Don't miss out - check it out now!

Last Updated : 04 Jul, 2023
Like Article
Save Article