What is CALLBACK? How it work?
what is the advantage of CALLBACK,
please explain with an example

Answer Posted / kishore kumar naik p

Call back functions are related to function pointers. To
understand this see the syntax of standard "qsort" below

void qsort(
void* base,
size_t num,
size_t width,
int (
__cdecl* compare
)(
const void* elem1,
const void* elem2
)
);
(refer MSDN for more info on "qsort")

In above syntax The fourth argument is function pointer.
So when we call this function we will send the address of
"Compare" function to "qsort" function and "Compare"
function will be called by the "qsort" depending on the
logic inside "qsort" function. In this case "Compare"
function is called back by the "qsort". So "Compare" is a
call back function here.

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