Function

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

Pass by Value

#include <iostream>

void increment(int num) {
    num = num + 1;
		return num;
}

int main() {
    int num = 5;
    std::cout << "Before the function: " << num << std::endl;
    increment(num);
    std::cout << "After the function: " << num << std::endl;
    return 0;
}

Boolean type