Why do we use a function pointer?

A function pointer, also called a subroutine pointer or procedure pointer, is a pointer that points to a function. Function pointers can be used to simplify code by providing a simple way to select a function to execute based on run-time values.

Why do we use function pointers in C++?

It is basically used to store the address of a function. We can call the function by using the function pointer, or we can also pass the pointer to another function as a parameter. They are mainly useful for event-driven applications, callbacks, and even for storing the functions in arrays.

How can a function pointer be an argument?

Pass-by-pointer means to pass a pointer argument in the calling function to the corresponding formal parameter of the called function. The called function can modify the value of the variable to which the pointer argument points. When you use pass-by-pointer, a copy of the pointer is passed to the function.

Which of the following is used to call a function without using the function name to send parameters?

Discussion Forum

How do you define a function pointer in C++?

Function Pointer Syntax It’s as if you’re declaring a function called “*foo”, which takes an int and returns void; now, if *foo is a function, then foo 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.)

What is the use of function pointers?

Function pointers can be useful when you want to create callback mechanism, and need to pass address of a function to another function. They can also be useful when you want to store an array of functions, to call dynamically for example. Callback routines appear to be the most common scenario put forth thus far.

Why can’t we pass a pointer to a variable into a function?

As we saw, we can’t pass in the variable itself because then we’d just be passing a copy, and any changes made to that copy would go away as soon as the function returned. But what if we passed a pointer to that variable into the function?

What is the starting address of a function called?

The starting address of a function is also called pointer of the function that can be assigned to another (function pointer type) variable. This function pointer type variable can be used to call the function. In this article I will not discuss much about the basics like syntax and all because that is frequently discussed in various places.

What is the best way to call a function in C++?

Pass a function pointer (or callable in general in C++). Flexible, less code, performance might suffer in some cases. Create a set of branches ( if / switch chain), if you know in advance the set of possible functions to call. Rigid, but might be faster than a function pointer for small number of branches. In C++, create a templated version.