Problem: Write a program that demonstrates different parameter passing methods: pass-by-value, pass-by-reference, and pass-by-pointer. The program should include a function that modifies the value of a variable using each parameter passing method.

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#include <iostream> // Function to demonstrate pass-by-value void passByValue(int num) {    num = 10; // Modify the local copy of num } // Function to demonstrate pass-by-reference void passByReference(int& num) {    num = 20; // Modify the original variable directly } // Function to demonstrate pass-by-pointer void passByPointer(int* numPtr) {    *numPtr = 30; // Modify the value pointed to by the pointer } int main() {    int num = 5;    std::cout << "Original value: " << num << std::endl;    passByValue(num);    std::cout << "After pass-by-value: " << num << std::endl;    passByReference(num);    std::cout << "After pass-by-reference: " << num << std::endl;    passByPointer(&num);    std::cout << "After pass-by-pointer: " << num << std::endl;    return 0; }

In this example, we define three functions to demonstrate different parameter passing methods.

The passByValue function takes an integer num by value. It modifies the local copy of num, which does not affect the original variable num in the main function.

The passByReference function takes an integer num by reference using the & operator. It modifies the original variable num directly. Any changes made to num inside the function are reflected in the main function.

The passByPointer function takes an integer pointer numPtr as a parameter. It modifies the value pointed to by the numPtr using the dereference operator *. The changes made to the value pointed to by numPtr are reflected in the main function.

In the main function, we initialize an integer variable num to 5. We then call each function with num as an argument and print the value of num after each call to observe the effects of different parameter passing methods.

By running the program, you'll see the different values of num as each parameter passing method is applied.