function

[Manyamanas]

how can a function be passed as a argument in another function......in c as well as c++

[techvinny]

you can do so by using pointer to function (function pointers)...

Declare a function pointer as though you were declaring a function
void (*ptofn)(int);

In this example, ptofn is a pointer to a function taking one argument, an integer, and that returns void. It's as if you're declaring a function called "*ptofn", which takes an int and returns void. Now, if *ptofn is a function, then ptofn must be a pointer to a function. (Similarly, a declaration like int *x can be read as *x is an int, so x must be a pointer to an int.)

To initialize the function pointer, you must assign it the address of a function in your program, as follows:

#include <stdio.h>
void myfunc(int x)
{
    printf( "%d\n", x );
}

int main()
{
    void (*ptofn)(int);
    ptofn = &myfunc; //pointer to function

    //now you could pass ptofn to any other function as a parameter so that you could invoke myfunc like this
    ptofn(10); //this would call myfunc and print out 10

    return 0;
}

HTH!!!

[dokepriya]

pass by value and pass by reference