User defined functions and variables in C++ programming

#include <iostream>

// Function prototypes
int add(int a, int b);
void greet();

// Global variable
int globalVariable = 10;

int main() {
    // Local variables
    int num1 = 5;
    int num2 = 7;

    // Function call
    int sum = add(num1, num2);

    // Output result
    std::cout << "Sum: " << sum << std::endl;

    // Function call
    greet();

    // Output global variable
    std::cout << "Global Variable: " << globalVariable << std::endl;

    return 0;
}

// Function definition
int add(int a, int b) {
    return a + b;
}

// Function definition
void greet() {
    std::cout << "Hello, User!" << std::endl;
}