Call by Value in C++ - Cyborg Coding

In C++, "call by value" is a mechanism for passing arguments to a function. When a function is called using call by value, the value of the argument is passed to the function, rather than the memory address of the variable. This means that the function operates on a copy of the argument, rather than the original variable.

Here is an example of a simple C++ program that demonstrates call by value:

#include <iostream>

void increment(int x) {

    x++;

}

int main() {

    int num = 5;

    increment(num);

    std::cout << "The value of num is: " << num << std::endl;

    return 0;

}

In this example, the main function calls the increment function with the value of the variable num as an argument. The increment function then increments the value of the local variable x by 1. However, since the main function passed the value of num rather than the memory address, the function operates on a copy of the value and the value of the original num variable remains unchanged. As a result, the output of the program will be The value of num is: 5.

Call by value is easy to understand and use, it's the default way of passing arguments in C++, it's also efficient because it does not require additional memory allocation to create a copy of the argument, also it provides a level of protection for the original variable, since the function cannot modify the original variable.

It's worth noting that call by value is not the only way to pass arguments to a function in C++, other mechanisms include call by reference and call by pointer.