Address of a function in C or C++

In C or C++, each variable is stored in memory and we can access its memory addresses using the address-of operator (&). Similarly, the functions are also stored in memory and also have their own memory addresses.

Accessing Address of a Function

To access the address we can use the function name without parenthesis. This is because adding parentheses means you're calling the function and without parentheses it will refer to its address.

C Example to Access Address of a Function

Here is the following example code in C, referring to the address of a function without using parentheses:

#include <stdio.h>

// here we define a function
void my_function() {
    printf("Hello World\n");
}

int main() {
    
    // calling the function normally by using parentheses
    printf("Calling function: ");
    my_function();

    // printing the function address without using parentheses
    printf("The address of my_function is: %p\n", (void*)my_function);
    
    // printing the address of the main() function without using parentheses
    printf("The address of main is: %p\n", (void*)main);

    return 0;
}

Output

Calling function: Hello World
The address of my_function is: 0x401136
The address of main is: 0x401147

C++ Example to Access Address of a Function

Here is the following example code in C++, referring to the address of a function without using parentheses:

#include <iostream>
using namespace std;

// here defining a simple function
void my_function() {
    cout << "Hello TutorialsPoint Learner!" << endl;
}

int main() {
    
    // here calling the function normally using parentheses
    cout << "Calling my_function: ";
    my_function();

    // here referring to the function's address without using parentheses
    cout << "The address of my_function is: " << (void*)my_function << endl;

    // here referring to the address of main function
    cout << "The address of main() function is: " << (void*)main << endl;

    return 0;
}

Output

Calling my_function: Hello TutorialsPoint Learner!
The address of my_function is: 0x55b31d78d189
The address of main() function is: 0x55b31d78d1bf