Write a program to swap the values of two number if values of both variables are not the same using user define functions

Pass-by-Value

In pass-by-value, a copy of the actual arguments is passed to the function. Any changes made to the parameters inside the function have no effect on the actual arguments.

Pass-by-Reference

In pass-by-reference, the actual arguments are passed to the function, allowing the function to modify the values of the arguments directly.

Program Implementation

#include <iostream>
using namespace std;

// Function to swap numbers using pass-by-value
void swapByValue(int a, int b) {
    if (a != b) {
        int temp = a;
        a = b;
        b = temp;
        cout << "Inside swapByValue (a, b): " << a << " " << b << endl;
    }
}

// Function to swap numbers using pass-by-reference
void swapByReference(int &a, int &b) {
    if (a != b) {
        int temp = a;
        a = b;
        b = temp;
        cout << "Inside swapByReference (a, b): " << a << " " << b << endl;
    }
}

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

    // Swap using pass-by-value
    cout << "Before swapByValue (x, y): " << x << " " << y << endl;
    swapByValue(x, y);
    cout << "After swapByValue (x, y): " << x << " " << y << endl;

    // Swap using pass-by-reference
    cout << "Before swapByReference (x, y): " << x << " " << y << endl;
    swapByReference(x, y);
    cout << "After swapByReference (x, y): " << x << " " << y << endl;

    return 0;
}

Explanation

1. swapByValue Function:
   • This function takes two integers as parameters by value.
   • It checks if the values are different, and if so, it swaps them using a temporary variable.
   • Since the function uses pass-by-value, changes made inside the function do not affect the original variables.
2. swapByReference Function:
   • This function takes two integers as parameters by reference.
   • It checks if the values are different, and if so, it swaps them using a temporary variable.
   • Since the function uses pass-by-reference, changes made inside the function directly affect the original variables.

Output

Before swapByValue (x, y): 5 10
Inside swapByValue (a, b): 10 5
After swapByValue (x, y): 5 10

Before swapByReference (x, y): 5 10
Inside swapByReference (a, b): 10 5
After swapByReference (x, y): 10 5

Key Points

• Pass-by-Value: The original values of x and y remain unchanged after the function call.
• Pass-by-Reference: The original values of x and y are swapped after the function call