What is a callback function?

Question

What is a callback function?

Answer 1

Assume we have a function sort(int *arraytobesorted,void (*algorithmchosen)(void)) where it can accept a function pointer as its argument which can be used at some point in sort()'s implementation . Then , here the code that is being addressed by the function pointer algorithmchosen is called as callback function .

And see the advantage is that we can choose any algorithm like:

  1.    algorithmchosen = bubblesort
  2.    algorithmchosen = heapsort
  3.    algorithmchosen = mergesort   ...

Which were, say,have been implemented with the prototype:

  1.   `void bubblesort(void)`
  2.   `void heapsort(void)`
  3.   `void mergesort(void)`   ...

This is a concept used in achieving Polymorphism in Object Oriented Programming