Problem: Write a program that swaps the values of two variables using references.

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#include <iostream> void swap(int& a, int& b) {    int temp = a;    a = b;    b = temp; } int main() {    int x = 10;    int y = 20;    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 this example, we define a function called swap that takes two integer references (a and b) as parameters. Inside the function, we use a temporary variable temp to swap the values of a and b.

In the main function, we declare two integer variables (x and y) and initialize them with values. We then call the swap function, passing x and y directly as arguments. Since swap accepts references, the function can directly modify the values of x and y.

Finally, we print the values of x and y before and after the swap to verify that the swap operation was successful.

By using references, we achieve pass-by-reference semantics, allowing the swap function to modify the original variables directly without the need for pointers or temporary storage.

You can modify and expand this code to practice using references in other scenarios or with different data types.