To define a reference parameter in C++, you can include an ampersand (&) symbol before the parameter name in the function signature. Here’s an example:

void swap(int& a, int& b) {
  int temp = a;
  a = b;
  b = temp;
}

int main() {
  int x = 5;
  int y = 10;

  std::cout << "Before swap: x = " << x << ", y = " << y << std::endl;

  swap(x, y);

  std::cout << "After swap: x = " << x << ", y = " << y << std::endl;

  return 0;
}

In the above example, the swap function takes two reference parameters a and b. Inside the function, the values of a and b are swapped using a temporary variable temp.

In the main function, two variables x and y are defined and assigned values. After calling the swap function, x and y are swapped because they were passed as reference parameters.

The output of the above code will be:

Before swap: x = 5, y = 10
After swap: x = 10, y = 5

Using reference parameters can be useful when you need to modify the value of a variable inside a function and have those changes reflected outside of the function. It provides a way to pass variables by reference rather than by value.

By using reference parameters effectively in your C++ code, you can write functions that can alter the state of variables directly, improving code readability and efficiency.

#C++ #ReferenceParameters