C Programming Code Examples C > Functions Code Examples how to declare a function pointer and how to call a function using this pointer how to declare a function pointer and how to call a function using this pointer In C programming language, we can have a concept of Pointer to a function known as function pointer in C. In this tutorial, we will learn how to declare a function pointer and how to call a function using this pointer. To understand this concept, you should have the basic knowledge of Functions and Pointers in C. Here double is a return type of function, p2f is name of the function pointer and (double, char) is an argument list of this function. Which means the first argument of this function is of double type and the second argument is char type. int sum (int number1, int number2) { return number1+number2; } int main() { /* The following two lines can also be written in a single * statement like this: void (*fun_ptr)(int) = &fun; */ int (*f2p) (int, int); f2p = sum; //Calling function using function pointer int op1 = f2p(10, 13); //Calling function in normal way using function name int op2 = sum(10, 13); printf("Output1: Call using function pointer: %d",op1); printf("\nOutput2: Call using function name: %d", op2); return 0; }