Passing Arguments - Pass by Reference Example in C++

 #include<iostream>

using namespace std;

// void changeA(int param) {

//     param = 20;

//     cout << param << "\n";

// }

// pass by reference using pointers

// void changeA(int *ptr) {

//     *ptr = 20;

//     cout << *ptr << "\n";

// }

// pass by reference using Reference variable

void changeA(int &param) {

    param = 20;

    cout << param << "\n";

}

int main(){

    int a = 10;

    int &b;

   

    changeA(a);

    cout << a << "\n";

    return 0;

}